Earth--Day and Night Regions
Tuesday, December 21, 2010
Today In History
from Human Events:
December 21, 1968
Apollo 8
On this day, the first manned space flight to leave earth’s orbit launched from Kennedy Space Center in Florida.
December 21, 1968
Apollo 8
On this day, the first manned space flight to leave earth’s orbit launched from Kennedy Space Center in Florida.
Sunday, December 19, 2010
The Twelve Stages Of Monday's Total Lunar Eclipse
From Space.com:
Yahoo! Buzz
The 12 Stages of Monday's Total Lunar Eclipse
By Joe Rao
SPACE.com Skywatching Columnist
posted: 19 December 2010
10:25 am ET
No enthusiastic sky watcher ever misses a total eclipse of the moon. The spectacle is often more beautiful and interesting than one would think. To prepare for the rare event on Dec. 20-21, here are some tips to keep in mind.
During the time that the moon is entering into, and later emerging from, the Earth's shadow, secondary phenomena may be overlooked. Below we describe 12 stages of a total lunar eclipse. [Lunar Eclipse Viewing Guide]
Amazing Spectacle: Total Lunar Eclipse Monday Night
By Joe Rao
SPACE.com Skywatching Columnist
posted: 17 December 2010
11:09 am ET
For a few hours on the night of Dec. 20 to Dec. 21, the attention of tens of millions of people will be drawn skyward, where the mottled, coppery globe of our moon will hang completely immersed in the long, tapering cone of shadow cast out into space by our Earth. If the weather is clear, favorably placed skywatchers will have a view of one of nature's most beautiful spectacles: a total eclipse of the moon.
Unlike a total eclipse of the sun, which is only visible to those in the path of totality, eclipses of the moon can usually be observed from one's own backyard. The passage of the moon through the Earth's shadow is equally visible from all places within the hemisphere where the moon is above the horizon.
The total phase of the upcoming event will be visible across all of North and South America, as well as the northern and western part of Europe, and a small part of northeast Asia, including Korea and much of Japan. Totality will also be visible in its entirety from the North Island of New Zealand and Hawaii — a potential viewing audience of about 1.5 billion people. This will be the first opportunity from any place on earth to see the moon undergo a total eclipse in 34 months. [Amazing photos of a total lunar eclipse]
Ads by GoogleMoon Eclipse Video ClipSearch multiple engines for moon eclipse video clip
www.webcrawler.comSatellite EarthGet Satellite Maps, Aerial Photos & More With The Free Maps Appbar
Maps.alot.comDanica Patrick Honda FilmDiscover the upside of failure from Honda racers and engineers.
www.honda.comThis star chart shows where in the sky the upcoming lunar eclipse will appear. And check this NASA lunar eclipse chart to see how visible the eclipse will be from different regions around the world.
Stages of the eclipse
There is nothing complicated about viewing this celestial spectacle. Unlike an eclipse of the sun, which necessitates special viewing precautions in order to avoid eye damage, an eclipse of the moon is perfectly safe to watch. All you'll need to watch are your eyes, but binoculars or a telescope will give a much nicer view.
The eclipse will actually begin when the moon enters the faint outer portion, or penumbra, of the Earth's shadow a little over an hour before it begins moving into the umbra. The penumbra, however, is all but invisible to the eye until the moon becomes deeply immersed in it. Sharp-eyed viewers may get their first glimpse of the penumbra as a faint smudge on the left part of the moon's disk at or around 6:15 UT (on Dec. 21) which corresponds to 1:15 a.m. Eastern Time or 10:15 p.m. Pacific Time (on Dec. 20).
The most noticeable part of this eclipse will come when the moon begins to enter the Earth's dark inner shadow (called the umbra). A small scallop of darkness will begin to appear on the moon's left edge at 6:33 UT (on Dec. 21) corresponding to 1:33 a.m. EST or 10:33 p.m. PST (on Dec. 20).
The moon is expected to take 3 hours and 28 minutes to pass completely through the umbra.
The total phase of the eclipse will last 72 minutes beginning at 7:41 UT (on Dec. 21), corresponding to 2:41 a.m. EST or 11:41 p.m. PST (on Dec. 20).
At the moment of mid-totality (8:17 UT/3:17 a.m. EST/12:17 a.m. PST), the moon will stand directly overhead from a point in the North Pacific Ocean about 800 miles (1,300 km) west of La Paz, Mexico.
The moon will pass entirely out of the Earth's umbra at 10:01 UT/5:01 a.m. EST/2:01 a.m. PST and the last evidence of the penumbra should vanish about 15 or 20 minutes later.
Color and brightness in question
During totality, although the moon will be entirely immersed in the Earth's shadow, it likely will not disappear from sight. Rather, it should appear to turn a coppery red color, a change caused by the Earth's atmosphere bending or refracting sunlight into the shadow.
Since the Earth's shadow is cone-shaped and extends out into space for about 844,000 miles (1,358,000 km), sunlight will be strained through a sort of "double sunset," all around the rim of the Earth, into its shadow and then onto the moon.
However, because of the recent eruptions of the Eyjafjallajökull volcano last spring and the Merapi volcano in Indonesia in October, one and possibly even two clouds of ash and dust might be floating high above the Earth. As a result, the moon may appear darker than usual during this eclipse; during totality, parts of the moon might even become black and invisible.
A careful description of the colors seen on the totally eclipsed moon and their changes is valuable. The hues depend on the optical equipment used, usually appearing more vivid with the naked eye than in telescopes. The French astronomer Andre-Louis Danjon introduced the following five-point scale of lunar luminosity ("L") to classify eclipses:
L = 0: Very dark eclipse, moon almost invisible, especially in mid-totality.
L = 1: Dark eclipse, gray or brownish coloration, details distinguishable only with difficulty.
L = 2: Deep red or rust-colored eclipse, with a very dark central part in the shadow, and outer edge of the umbra relatively bright.
L = 3: Brick red eclipse, usually with a bright or yellow rim to the shadow.
L = 4: Very bright copper-red or orange eclipse, with a bluish very bright shadow rim.
Examine the moon at mid-totality and also near the beginning and end of totality to get an impression of both the inner and outer umbra. In noting an L observation, state the time and optical means (naked eye, binoculars or telescope) that is used. We invite readers to e-mail their Danjon estimate for this eclipse (along with any pictures they'd like to share) to cmoskowitz-at-SPACE.com.
At mid-totality, from rural locations far from city lights, the darkness of the sky is impressive. Faint stars and the Milky Way will appear, and the surrounding landscape will take on a somber hue. As totality ends, the eastern edge of the moon begins to emerge from the umbra, and the sequence of events repeats in reverse order until the spectacle is over.
Fringe effects
Interestingly, from most of New Zealand, a slice of northeast Australia, Papua, New Guinea, southwest Japan and Korea, the moon will rise during totality on the evening of Dec. 21. Because of low altitude and bright evening twilight, observers in these locations may not see much of the moon at all until it begins to emerge from out of the Earth's shadow.
Conversely, much of the United Kingdom and parts of western and northern Europe will see the moon set during totality on the morning of Dec. 21. Because of low altitude and bright morning twilight, observers in these locations may not see much of the moon at all after it slips completely into the Earth's shadow.
Past and future
The last total lunar eclipse occurred on Feb. 20 to Feb. 21, 2008 and was visible from most of the Americas, as well as Europe, much of Africa and western Asia. In 2011, there will be two total lunar eclipses. The first, on June 15, will be visible primarily from the Eastern Hemisphere and will have an unusually long duration of totality lasting one hour and 40 minutes.
Another total lunar eclipse will occur on Dec. 10 and will be visible over the western half of North America before moonset. For the next total lunar eclipse that will be visible across all of North America, we must wait until April 14 to April 15, 2014.
Probably not all of those mentioned will occur because no two eclipses are exactly the same. But many will, and those who know what to look for have a better chance of seeing them! [Amazing photos of a total lunar eclipse]
Ads by GoogleMoon Eclipse Video ClipSearch multiple engines for moon eclipse video clip
www.webcrawler.comFree Space WallpapersGet Cool Space Desktop Wallpapers w Planets, Moons & Stars-Try Them Now
wallpapers.smileycentral.comDanica Patrick Honda FilmDiscover the upside of failure from Honda racers and engineers.
www.honda.comClick here for a table showing the times of all 12 stages in different time zones. This star chart shows where in the sky the upcoming lunar eclipse will appear.
The various stages, fully described:
1) Moon enters penumbra (12:29 a.m. EST/9:29 p.m. PST) The shadow cone of the earth has two parts: a dark, inner umbra, surrounded by a lighter penumbra. The penumbra is the pale outer portion of the Earth's shadow. Although the eclipse begins officially at this moment, this is in essence an academic event. You won't see anything unusual happening to the moon - at least not just yet.
The Earth's penumbral shadow is so faint that it remains invisible until the moon is deeply immersed in it. We must wait until the penumbra has reached roughly 70 percent across the moon's disk. For about the next 45 minutes the full moon will continue to appear to shine normally although with each passing minute it is progressing ever deeper into the Earth's outer shadow.
2) Penumbral shadow begins to appear (1:13 a.m. EST/10:13 p.m. PST) Now the moon has progressed far enough into the penumbra so that it should be evident on its disk. Start looking for a very subtle light shading to appear on the moon's upper left portion. This will become increasingly more and more evident as the minutes pass; the shading will appear to spread and deepen. Just before the moon begins to enter the Earth's dark umbral shadow the penumbra should appear as an obvious smudge or tarnish on the moon's left portion.
3) Moon enters umbra (1:33 a.m. EST/10:33 p.m. PST) The moon now begins to cross into the Earth's dark central shadow, called the umbra. A small dark scallop begins to appear on the moon's upper left-hand (northeastern) limb. The partial phases of the eclipse begin; the pace quickens and the change is dramatic. The umbra is much darker than the penumbra and fairly sharp-edged.
As the minutes pass the dark shadow appears to slowly creep across the moon's face. At first the moon's limb may seem to vanish completely inside of the umbra, but much later, as it moves in deeper you'll probably notice it glowing dimly orange, red or brown. Notice also that the edge of the Earth's shadow projected on the moon is curved. Here is visible evidence that the Earth is a sphere, as deduced by Aristotle from Iunar eclipses he observed in the 4th century B.C.
Almost as if a dimmer switch was slowly being turned down, the surrounding landscape and deep shadows of a brilliant moonlit night begin to fade away.
4) 75 percent coverage (2:23 a.m. EST/11:23 p.m. EST) With three-quarters of the moon's disk now eclipsed, that part of it that is immersed in shadow should begin to very faintly light up similar to a piece of iron heated to the point where it just begins to glow. It now becomes obvious that the umbral shadow is not complete darkness. Using binoculars or a telescope, its outer part is usually light enough to reveal lunar seas and craters, but the central part is much darker, and sometimes no surface features are recognizable.
Colors in the umbra vary greatly from one eclipse to the next. Reds and grays usually predominate, but sometimes browns, blues and other tints are encountered.
5) Less than five minutes to totality (2:37 a.m. EST/11:37 p.m. PST) Several minutes before (and after) totality, the contrast between the remaining pale-yellow sliver and the ruddy-brown coloration spread over the rest of the moon's disk may produce a beautiful phenomenon known to some as the "Japanese lantern effect. "
6) Total eclipse begins (2:41 a.m. EST/11:41 p.m. PST) When the last of the moon enters the umbra, the total eclipse begins. How the moon will appear during totality is not known. Some eclipses are such a dark gray-black that the moon nearly vanishes from view. During other eclipses it can glow a bright orange.
The reason the moon can be seen at all when totally eclipsed is that sunlight is scattered and refracted around the edge of the Earth by our atmosphere. To an astronaut standing on the moon during totality, the sun would be hidden behind a dark Earth outlined by a brilliant red ring consisting of all the world's sunrises and sunsets.
The brightness of this ring around the earth depends on global weather conditions and the amount of dust suspended in the air. A clear atmosphere on Earth means a bright lunar eclipse. If a major volcanic eruption has injected particles into the stratosphere, the eclipse is very dark.
Because of the recent eruptions of the Eyjafjallajökull volcano in Iceland last spring and the Merapi volcano in Indonesia in October, one and possibly two clouds of ash and dust might be currently floating high above the Earth. As a result, the moon may appear darker than usual during this eclipse; during totality, parts of the moon might even become black and invisible.
7) Middle of totality (3:17 a.m. EST/12:17 a.m. PST)The moon is now shining anywhere from 10,000 to 100,000 times fainter than it was just a couple of hours ago.
Since the moon is moving to the north of the center of the Earth's umbra, the gradation of color and brightness across the lunar disk should be such that its lower portion should appear darkest, with hues of deep copper or chocolate brown. Meanwhile, its upper portion – that part of the moon closest to the outer edge of the umbra should appear brightest, with hues of reds, oranges and even perhaps a soft bluish-white.
Observers away from bright city lights will notice a much greater number of stars than were visible earlier in the night. The darkened moon will be near the constellation Taurus, just beyond the tips of the bull's horns and hovering high above the stars of Orion, the hunter.
The darkness of the sky is impressive. The surrounding landscape has taken on a somber hue. Before the eclipse, the full moon looked flat and one-dimensional. During totality, however, it will look smaller and three-dimensional – like some weirdly illuminated ball suspended in space.
Before the moon entered the Earth's shadow, the temperature at the lunar equator on its sunlit surface hovered at 260 degrees F (127 degrees C). Since the moon lacks an atmosphere, there is no way that this heat could be retained from escaping into space as the shadow sweeps by.
Now, in shadow, the temperature on the moon has plummeted to minus 280 degrees F (minus 173 degrees C). A drop of over 500 degrees F (300 degrees C) in only about two hours!
8) Total eclipse ends (3:53 a.m. EST/12:53 am. PST) The emergence of the moon from the shadow begins. The first small segment of the moon begins to reappear, followed again for the next several minutes by the Japanese Lantern Effect.
9) 75 percent coverage (4:10 a.m. EST/1:10 a.m. PST) Any vestiges of coloration within the umbra should be disappearing now. From here on out, as the dark shadow methodically creeps off the moon's disk it should appear black and featureless.
10) Moon leaves umbra (5:01 a.m. EST/2:01 a.m. PST) The dark central shadow clears the moon's upper right hand (northwestern) limb.
11) Penumbra shadow fades away (5:20 a.m. EST/2:20 p.m. PST) As the last, faint shading vanishes off the moon's upper right portion, the visual show comes to an end.
12) Moon leaves penumbra (6:04 a.m. EST/3:04 p.m. PST) The eclipse officially ends, as the moon is completely free of the penumbral shadow.
Yahoo! Buzz
The 12 Stages of Monday's Total Lunar Eclipse
By Joe Rao
SPACE.com Skywatching Columnist
posted: 19 December 2010
10:25 am ET
No enthusiastic sky watcher ever misses a total eclipse of the moon. The spectacle is often more beautiful and interesting than one would think. To prepare for the rare event on Dec. 20-21, here are some tips to keep in mind.
During the time that the moon is entering into, and later emerging from, the Earth's shadow, secondary phenomena may be overlooked. Below we describe 12 stages of a total lunar eclipse. [Lunar Eclipse Viewing Guide]
Amazing Spectacle: Total Lunar Eclipse Monday Night
By Joe Rao
SPACE.com Skywatching Columnist
posted: 17 December 2010
11:09 am ET
For a few hours on the night of Dec. 20 to Dec. 21, the attention of tens of millions of people will be drawn skyward, where the mottled, coppery globe of our moon will hang completely immersed in the long, tapering cone of shadow cast out into space by our Earth. If the weather is clear, favorably placed skywatchers will have a view of one of nature's most beautiful spectacles: a total eclipse of the moon.
Unlike a total eclipse of the sun, which is only visible to those in the path of totality, eclipses of the moon can usually be observed from one's own backyard. The passage of the moon through the Earth's shadow is equally visible from all places within the hemisphere where the moon is above the horizon.
The total phase of the upcoming event will be visible across all of North and South America, as well as the northern and western part of Europe, and a small part of northeast Asia, including Korea and much of Japan. Totality will also be visible in its entirety from the North Island of New Zealand and Hawaii — a potential viewing audience of about 1.5 billion people. This will be the first opportunity from any place on earth to see the moon undergo a total eclipse in 34 months. [Amazing photos of a total lunar eclipse]
Ads by GoogleMoon Eclipse Video ClipSearch multiple engines for moon eclipse video clip
www.webcrawler.comSatellite EarthGet Satellite Maps, Aerial Photos & More With The Free Maps Appbar
Maps.alot.comDanica Patrick Honda FilmDiscover the upside of failure from Honda racers and engineers.
www.honda.comThis star chart shows where in the sky the upcoming lunar eclipse will appear. And check this NASA lunar eclipse chart to see how visible the eclipse will be from different regions around the world.
Stages of the eclipse
There is nothing complicated about viewing this celestial spectacle. Unlike an eclipse of the sun, which necessitates special viewing precautions in order to avoid eye damage, an eclipse of the moon is perfectly safe to watch. All you'll need to watch are your eyes, but binoculars or a telescope will give a much nicer view.
The eclipse will actually begin when the moon enters the faint outer portion, or penumbra, of the Earth's shadow a little over an hour before it begins moving into the umbra. The penumbra, however, is all but invisible to the eye until the moon becomes deeply immersed in it. Sharp-eyed viewers may get their first glimpse of the penumbra as a faint smudge on the left part of the moon's disk at or around 6:15 UT (on Dec. 21) which corresponds to 1:15 a.m. Eastern Time or 10:15 p.m. Pacific Time (on Dec. 20).
The most noticeable part of this eclipse will come when the moon begins to enter the Earth's dark inner shadow (called the umbra). A small scallop of darkness will begin to appear on the moon's left edge at 6:33 UT (on Dec. 21) corresponding to 1:33 a.m. EST or 10:33 p.m. PST (on Dec. 20).
The moon is expected to take 3 hours and 28 minutes to pass completely through the umbra.
The total phase of the eclipse will last 72 minutes beginning at 7:41 UT (on Dec. 21), corresponding to 2:41 a.m. EST or 11:41 p.m. PST (on Dec. 20).
At the moment of mid-totality (8:17 UT/3:17 a.m. EST/12:17 a.m. PST), the moon will stand directly overhead from a point in the North Pacific Ocean about 800 miles (1,300 km) west of La Paz, Mexico.
The moon will pass entirely out of the Earth's umbra at 10:01 UT/5:01 a.m. EST/2:01 a.m. PST and the last evidence of the penumbra should vanish about 15 or 20 minutes later.
Color and brightness in question
During totality, although the moon will be entirely immersed in the Earth's shadow, it likely will not disappear from sight. Rather, it should appear to turn a coppery red color, a change caused by the Earth's atmosphere bending or refracting sunlight into the shadow.
Since the Earth's shadow is cone-shaped and extends out into space for about 844,000 miles (1,358,000 km), sunlight will be strained through a sort of "double sunset," all around the rim of the Earth, into its shadow and then onto the moon.
However, because of the recent eruptions of the Eyjafjallajökull volcano last spring and the Merapi volcano in Indonesia in October, one and possibly even two clouds of ash and dust might be floating high above the Earth. As a result, the moon may appear darker than usual during this eclipse; during totality, parts of the moon might even become black and invisible.
A careful description of the colors seen on the totally eclipsed moon and their changes is valuable. The hues depend on the optical equipment used, usually appearing more vivid with the naked eye than in telescopes. The French astronomer Andre-Louis Danjon introduced the following five-point scale of lunar luminosity ("L") to classify eclipses:
L = 0: Very dark eclipse, moon almost invisible, especially in mid-totality.
L = 1: Dark eclipse, gray or brownish coloration, details distinguishable only with difficulty.
L = 2: Deep red or rust-colored eclipse, with a very dark central part in the shadow, and outer edge of the umbra relatively bright.
L = 3: Brick red eclipse, usually with a bright or yellow rim to the shadow.
L = 4: Very bright copper-red or orange eclipse, with a bluish very bright shadow rim.
Examine the moon at mid-totality and also near the beginning and end of totality to get an impression of both the inner and outer umbra. In noting an L observation, state the time and optical means (naked eye, binoculars or telescope) that is used. We invite readers to e-mail their Danjon estimate for this eclipse (along with any pictures they'd like to share) to cmoskowitz-at-SPACE.com.
At mid-totality, from rural locations far from city lights, the darkness of the sky is impressive. Faint stars and the Milky Way will appear, and the surrounding landscape will take on a somber hue. As totality ends, the eastern edge of the moon begins to emerge from the umbra, and the sequence of events repeats in reverse order until the spectacle is over.
Fringe effects
Interestingly, from most of New Zealand, a slice of northeast Australia, Papua, New Guinea, southwest Japan and Korea, the moon will rise during totality on the evening of Dec. 21. Because of low altitude and bright evening twilight, observers in these locations may not see much of the moon at all until it begins to emerge from out of the Earth's shadow.
Conversely, much of the United Kingdom and parts of western and northern Europe will see the moon set during totality on the morning of Dec. 21. Because of low altitude and bright morning twilight, observers in these locations may not see much of the moon at all after it slips completely into the Earth's shadow.
Past and future
The last total lunar eclipse occurred on Feb. 20 to Feb. 21, 2008 and was visible from most of the Americas, as well as Europe, much of Africa and western Asia. In 2011, there will be two total lunar eclipses. The first, on June 15, will be visible primarily from the Eastern Hemisphere and will have an unusually long duration of totality lasting one hour and 40 minutes.
Another total lunar eclipse will occur on Dec. 10 and will be visible over the western half of North America before moonset. For the next total lunar eclipse that will be visible across all of North America, we must wait until April 14 to April 15, 2014.
Probably not all of those mentioned will occur because no two eclipses are exactly the same. But many will, and those who know what to look for have a better chance of seeing them! [Amazing photos of a total lunar eclipse]
Ads by GoogleMoon Eclipse Video ClipSearch multiple engines for moon eclipse video clip
www.webcrawler.comFree Space WallpapersGet Cool Space Desktop Wallpapers w Planets, Moons & Stars-Try Them Now
wallpapers.smileycentral.comDanica Patrick Honda FilmDiscover the upside of failure from Honda racers and engineers.
www.honda.comClick here for a table showing the times of all 12 stages in different time zones. This star chart shows where in the sky the upcoming lunar eclipse will appear.
The various stages, fully described:
1) Moon enters penumbra (12:29 a.m. EST/9:29 p.m. PST) The shadow cone of the earth has two parts: a dark, inner umbra, surrounded by a lighter penumbra. The penumbra is the pale outer portion of the Earth's shadow. Although the eclipse begins officially at this moment, this is in essence an academic event. You won't see anything unusual happening to the moon - at least not just yet.
The Earth's penumbral shadow is so faint that it remains invisible until the moon is deeply immersed in it. We must wait until the penumbra has reached roughly 70 percent across the moon's disk. For about the next 45 minutes the full moon will continue to appear to shine normally although with each passing minute it is progressing ever deeper into the Earth's outer shadow.
2) Penumbral shadow begins to appear (1:13 a.m. EST/10:13 p.m. PST) Now the moon has progressed far enough into the penumbra so that it should be evident on its disk. Start looking for a very subtle light shading to appear on the moon's upper left portion. This will become increasingly more and more evident as the minutes pass; the shading will appear to spread and deepen. Just before the moon begins to enter the Earth's dark umbral shadow the penumbra should appear as an obvious smudge or tarnish on the moon's left portion.
3) Moon enters umbra (1:33 a.m. EST/10:33 p.m. PST) The moon now begins to cross into the Earth's dark central shadow, called the umbra. A small dark scallop begins to appear on the moon's upper left-hand (northeastern) limb. The partial phases of the eclipse begin; the pace quickens and the change is dramatic. The umbra is much darker than the penumbra and fairly sharp-edged.
As the minutes pass the dark shadow appears to slowly creep across the moon's face. At first the moon's limb may seem to vanish completely inside of the umbra, but much later, as it moves in deeper you'll probably notice it glowing dimly orange, red or brown. Notice also that the edge of the Earth's shadow projected on the moon is curved. Here is visible evidence that the Earth is a sphere, as deduced by Aristotle from Iunar eclipses he observed in the 4th century B.C.
Almost as if a dimmer switch was slowly being turned down, the surrounding landscape and deep shadows of a brilliant moonlit night begin to fade away.
4) 75 percent coverage (2:23 a.m. EST/11:23 p.m. EST) With three-quarters of the moon's disk now eclipsed, that part of it that is immersed in shadow should begin to very faintly light up similar to a piece of iron heated to the point where it just begins to glow. It now becomes obvious that the umbral shadow is not complete darkness. Using binoculars or a telescope, its outer part is usually light enough to reveal lunar seas and craters, but the central part is much darker, and sometimes no surface features are recognizable.
Colors in the umbra vary greatly from one eclipse to the next. Reds and grays usually predominate, but sometimes browns, blues and other tints are encountered.
5) Less than five minutes to totality (2:37 a.m. EST/11:37 p.m. PST) Several minutes before (and after) totality, the contrast between the remaining pale-yellow sliver and the ruddy-brown coloration spread over the rest of the moon's disk may produce a beautiful phenomenon known to some as the "Japanese lantern effect. "
6) Total eclipse begins (2:41 a.m. EST/11:41 p.m. PST) When the last of the moon enters the umbra, the total eclipse begins. How the moon will appear during totality is not known. Some eclipses are such a dark gray-black that the moon nearly vanishes from view. During other eclipses it can glow a bright orange.
The reason the moon can be seen at all when totally eclipsed is that sunlight is scattered and refracted around the edge of the Earth by our atmosphere. To an astronaut standing on the moon during totality, the sun would be hidden behind a dark Earth outlined by a brilliant red ring consisting of all the world's sunrises and sunsets.
The brightness of this ring around the earth depends on global weather conditions and the amount of dust suspended in the air. A clear atmosphere on Earth means a bright lunar eclipse. If a major volcanic eruption has injected particles into the stratosphere, the eclipse is very dark.
Because of the recent eruptions of the Eyjafjallajökull volcano in Iceland last spring and the Merapi volcano in Indonesia in October, one and possibly two clouds of ash and dust might be currently floating high above the Earth. As a result, the moon may appear darker than usual during this eclipse; during totality, parts of the moon might even become black and invisible.
7) Middle of totality (3:17 a.m. EST/12:17 a.m. PST)The moon is now shining anywhere from 10,000 to 100,000 times fainter than it was just a couple of hours ago.
Since the moon is moving to the north of the center of the Earth's umbra, the gradation of color and brightness across the lunar disk should be such that its lower portion should appear darkest, with hues of deep copper or chocolate brown. Meanwhile, its upper portion – that part of the moon closest to the outer edge of the umbra should appear brightest, with hues of reds, oranges and even perhaps a soft bluish-white.
Observers away from bright city lights will notice a much greater number of stars than were visible earlier in the night. The darkened moon will be near the constellation Taurus, just beyond the tips of the bull's horns and hovering high above the stars of Orion, the hunter.
The darkness of the sky is impressive. The surrounding landscape has taken on a somber hue. Before the eclipse, the full moon looked flat and one-dimensional. During totality, however, it will look smaller and three-dimensional – like some weirdly illuminated ball suspended in space.
Before the moon entered the Earth's shadow, the temperature at the lunar equator on its sunlit surface hovered at 260 degrees F (127 degrees C). Since the moon lacks an atmosphere, there is no way that this heat could be retained from escaping into space as the shadow sweeps by.
Now, in shadow, the temperature on the moon has plummeted to minus 280 degrees F (minus 173 degrees C). A drop of over 500 degrees F (300 degrees C) in only about two hours!
8) Total eclipse ends (3:53 a.m. EST/12:53 am. PST) The emergence of the moon from the shadow begins. The first small segment of the moon begins to reappear, followed again for the next several minutes by the Japanese Lantern Effect.
9) 75 percent coverage (4:10 a.m. EST/1:10 a.m. PST) Any vestiges of coloration within the umbra should be disappearing now. From here on out, as the dark shadow methodically creeps off the moon's disk it should appear black and featureless.
10) Moon leaves umbra (5:01 a.m. EST/2:01 a.m. PST) The dark central shadow clears the moon's upper right hand (northwestern) limb.
11) Penumbra shadow fades away (5:20 a.m. EST/2:20 p.m. PST) As the last, faint shading vanishes off the moon's upper right portion, the visual show comes to an end.
12) Moon leaves penumbra (6:04 a.m. EST/3:04 p.m. PST) The eclipse officially ends, as the moon is completely free of the penumbral shadow.
Friday, December 17, 2010
Amazing Spectacle: Total Lunar Eclipse Monday Night
From Space.com:
Amazing Spectacle: Total Lunar Eclipse Monday Night
By Joe Rao
SPACE.com Skywatching Columnist
posted: 17 December 2010
11:09 am ET
For a few hours on the night of Dec. 20 to Dec. 21, the attention of tens of millions of people will be drawn skyward, where the mottled, coppery globe of our moon will hang completely immersed in the long, tapering cone of shadow cast out into space by our Earth. If the weather is clear, favorably placed skywatchers will have a view of one of nature's most beautiful spectacles: a total eclipse of the moon.
Unlike a total eclipse of the sun, which is only visible to those in the path of totality, eclipses of the moon can usually be observed from one's own backyard. The passage of the moon through the Earth's shadow is equally visible from all places within the hemisphere where the moon is above the horizon.
The total phase of the upcoming event will be visible across all of North and South America, as well as the northern and western part of Europe, and a small part of northeast Asia, including Korea and much of Japan. Totality will also be visible in its entirety from the North Island of New Zealand and Hawaii — a potential viewing audience of about 1.5 billion people. This will be the first opportunity from any place on earth to see the moon undergo a total eclipse in 34 months. [Amazing photos of a total lunar eclipse]
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AboutAstro.com/zodiacMoon Eclipse Video ClipSearch multiple engines for moon eclipse video clip
www.webcrawler.comThis star chart shows where in the sky the upcoming lunar eclipse will appear. And check this NASA lunar eclipse chart to see how visible the eclipse will be from different regions around the world.
Stages of the eclipse
There is nothing complicated about viewing this celestial spectacle. Unlike an eclipse of the sun, which necessitates special viewing precautions in order to avoid eye damage, an eclipse of the moon is perfectly safe to watch. All you'll need to watch are your eyes, but binoculars or a telescope will give a much nicer view.
The eclipse will actually begin when the moon enters the faint outer portion, or penumbra, of the Earth's shadow a little over an hour before it begins moving into the umbra. The penumbra, however, is all but invisible to the eye until the moon becomes deeply immersed in it. Sharp-eyed viewers may get their first glimpse of the penumbra as a faint smudge on the left part of the moon's disk at or around 6:15 UT (on Dec. 21) which corresponds to 1:15 a.m. Eastern Time or 10:15 p.m. Pacific Time (on Dec. 20).
The most noticeable part of this eclipse will come when the moon begins to enter the Earth's dark inner shadow (called the umbra). A small scallop of darkness will begin to appear on the moon's left edge at 6:33 UT (on Dec. 21) corresponding to 1:33 a.m. EST or 10:33 p.m. PST (on Dec. 20).
The moon is expected to take 3 hours and 28 minutes to pass completely through the umbra.
The total phase of the eclipse will last 72 minutes beginning at 7:41 UT (on Dec. 21), corresponding to 2:41 a.m. EST or 11:41 p.m. PST (on Dec. 20).
At the moment of mid-totality (8:17 UT/3:17 a.m. EST/12:17 a.m. PST), the moon will stand directly overhead from a point in the North Pacific Ocean about 800 miles (1,300 km) west of La Paz, Mexico.
The moon will pass entirely out of the Earth's umbra at 10:01 UT/5:01 a.m. EST/2:01 a.m. PST and the last evidence of the penumbra should vanish about 15 or 20 minutes later.
Color and brightness in question
During totality, although the moon will be entirely immersed in the Earth's shadow, it likely will not disappear from sight. Rather, it should appear to turn a coppery red color, a change caused by the Earth's atmosphere bending or refracting sunlight into the shadow.
Since the Earth's shadow is cone-shaped and extends out into space for about 844,000 miles (1,358,000 km), sunlight will be strained through a sort of "double sunset," all around the rim of the Earth, into its shadow and then onto the moon.
However, because of the recent eruptions of the Eyjafjallajökull volcano last spring and the Merapi volcano in Indonesia in October, one and possibly even two clouds of ash and dust might be floating high above the Earth. As a result, the moon may appear darker than usual during this eclipse; during totality, parts of the moon might even become black and invisible.
A careful description of the colors seen on the totally eclipsed moon and their changes is valuable. The hues depend on the optical equipment used, usually appearing more vivid with the naked eye than in telescopes. The French astronomer Andre-Louis Danjon introduced the following five-point scale of lunar luminosity ("L") to classify eclipses:
L = 0: Very dark eclipse, moon almost invisible, especially in mid-totality.
L = 1: Dark eclipse, gray or brownish coloration, details distinguishable only with difficulty.
L = 2: Deep red or rust-colored eclipse, with a very dark central part in the shadow, and outer edge of the umbra relatively bright.
L = 3: Brick red eclipse, usually with a bright or yellow rim to the shadow.
L = 4: Very bright copper-red or orange eclipse, with a bluish very bright shadow rim.
Examine the moon at mid-totality and also near the beginning and end of totality to get an impression of both the inner and outer umbra. In noting an L observation, state the time and optical means (naked eye, binoculars or telescope) that is used. We invite readers to e-mail their Danjon estimate for this eclipse (along with any pictures they'd like to share) to cmoskowitz-at-SPACE.com.
At mid-totality, from rural locations far from city lights, the darkness of the sky is impressive. Faint stars and the Milky Way will appear, and the surrounding landscape will take on a somber hue. As totality ends, the eastern edge of the moon begins to emerge from the umbra, and the sequence of events repeats in reverse order until the spectacle is over.
Fringe effects
Interestingly, from most of New Zealand, a slice of northeast Australia, Papua, New Guinea, southwest Japan and Korea, the moon will rise during totality on the evening of Dec. 21. Because of low altitude and bright evening twilight, observers in these locations may not see much of the moon at all until it begins to emerge from out of the Earth's shadow.
Conversely, much of the United Kingdom and parts of western and northern Europe will see the moon set during totality on the morning of Dec. 21. Because of low altitude and bright morning twilight, observers in these locations may not see much of the moon at all after it slips completely into the Earth's shadow.
Past and future
The last total lunar eclipse occurred on Feb. 20 to Feb. 21, 2008 and was visible from most of the Americas, as well as Europe, much of Africa and western Asia. In 2011, there will be two total lunar eclipses. The first, on June 15, will be visible primarily from the Eastern Hemisphere and will have an unusually long duration of totality lasting one hour and 40 minutes.
Another total lunar eclipse will occur on Dec. 10 and will be visible over the western half of North America before moonset. For the next total lunar eclipse that will be visible across all of North America, we must wait until April 14 to April 15, 2014.
Amazing Spectacle: Total Lunar Eclipse Monday Night
By Joe Rao
SPACE.com Skywatching Columnist
posted: 17 December 2010
11:09 am ET
For a few hours on the night of Dec. 20 to Dec. 21, the attention of tens of millions of people will be drawn skyward, where the mottled, coppery globe of our moon will hang completely immersed in the long, tapering cone of shadow cast out into space by our Earth. If the weather is clear, favorably placed skywatchers will have a view of one of nature's most beautiful spectacles: a total eclipse of the moon.
Unlike a total eclipse of the sun, which is only visible to those in the path of totality, eclipses of the moon can usually be observed from one's own backyard. The passage of the moon through the Earth's shadow is equally visible from all places within the hemisphere where the moon is above the horizon.
The total phase of the upcoming event will be visible across all of North and South America, as well as the northern and western part of Europe, and a small part of northeast Asia, including Korea and much of Japan. Totality will also be visible in its entirety from the North Island of New Zealand and Hawaii — a potential viewing audience of about 1.5 billion people. This will be the first opportunity from any place on earth to see the moon undergo a total eclipse in 34 months. [Amazing photos of a total lunar eclipse]
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www.BoeingStore.comYour Zodiac HoroscopeInsert Your Birthdate & Get Answers about Past-Present and Future. Free
AboutAstro.com/zodiacMoon Eclipse Video ClipSearch multiple engines for moon eclipse video clip
www.webcrawler.comThis star chart shows where in the sky the upcoming lunar eclipse will appear. And check this NASA lunar eclipse chart to see how visible the eclipse will be from different regions around the world.
Stages of the eclipse
There is nothing complicated about viewing this celestial spectacle. Unlike an eclipse of the sun, which necessitates special viewing precautions in order to avoid eye damage, an eclipse of the moon is perfectly safe to watch. All you'll need to watch are your eyes, but binoculars or a telescope will give a much nicer view.
The eclipse will actually begin when the moon enters the faint outer portion, or penumbra, of the Earth's shadow a little over an hour before it begins moving into the umbra. The penumbra, however, is all but invisible to the eye until the moon becomes deeply immersed in it. Sharp-eyed viewers may get their first glimpse of the penumbra as a faint smudge on the left part of the moon's disk at or around 6:15 UT (on Dec. 21) which corresponds to 1:15 a.m. Eastern Time or 10:15 p.m. Pacific Time (on Dec. 20).
The most noticeable part of this eclipse will come when the moon begins to enter the Earth's dark inner shadow (called the umbra). A small scallop of darkness will begin to appear on the moon's left edge at 6:33 UT (on Dec. 21) corresponding to 1:33 a.m. EST or 10:33 p.m. PST (on Dec. 20).
The moon is expected to take 3 hours and 28 minutes to pass completely through the umbra.
The total phase of the eclipse will last 72 minutes beginning at 7:41 UT (on Dec. 21), corresponding to 2:41 a.m. EST or 11:41 p.m. PST (on Dec. 20).
At the moment of mid-totality (8:17 UT/3:17 a.m. EST/12:17 a.m. PST), the moon will stand directly overhead from a point in the North Pacific Ocean about 800 miles (1,300 km) west of La Paz, Mexico.
The moon will pass entirely out of the Earth's umbra at 10:01 UT/5:01 a.m. EST/2:01 a.m. PST and the last evidence of the penumbra should vanish about 15 or 20 minutes later.
Color and brightness in question
During totality, although the moon will be entirely immersed in the Earth's shadow, it likely will not disappear from sight. Rather, it should appear to turn a coppery red color, a change caused by the Earth's atmosphere bending or refracting sunlight into the shadow.
Since the Earth's shadow is cone-shaped and extends out into space for about 844,000 miles (1,358,000 km), sunlight will be strained through a sort of "double sunset," all around the rim of the Earth, into its shadow and then onto the moon.
However, because of the recent eruptions of the Eyjafjallajökull volcano last spring and the Merapi volcano in Indonesia in October, one and possibly even two clouds of ash and dust might be floating high above the Earth. As a result, the moon may appear darker than usual during this eclipse; during totality, parts of the moon might even become black and invisible.
A careful description of the colors seen on the totally eclipsed moon and their changes is valuable. The hues depend on the optical equipment used, usually appearing more vivid with the naked eye than in telescopes. The French astronomer Andre-Louis Danjon introduced the following five-point scale of lunar luminosity ("L") to classify eclipses:
L = 0: Very dark eclipse, moon almost invisible, especially in mid-totality.
L = 1: Dark eclipse, gray or brownish coloration, details distinguishable only with difficulty.
L = 2: Deep red or rust-colored eclipse, with a very dark central part in the shadow, and outer edge of the umbra relatively bright.
L = 3: Brick red eclipse, usually with a bright or yellow rim to the shadow.
L = 4: Very bright copper-red or orange eclipse, with a bluish very bright shadow rim.
Examine the moon at mid-totality and also near the beginning and end of totality to get an impression of both the inner and outer umbra. In noting an L observation, state the time and optical means (naked eye, binoculars or telescope) that is used. We invite readers to e-mail their Danjon estimate for this eclipse (along with any pictures they'd like to share) to cmoskowitz-at-SPACE.com.
At mid-totality, from rural locations far from city lights, the darkness of the sky is impressive. Faint stars and the Milky Way will appear, and the surrounding landscape will take on a somber hue. As totality ends, the eastern edge of the moon begins to emerge from the umbra, and the sequence of events repeats in reverse order until the spectacle is over.
Fringe effects
Interestingly, from most of New Zealand, a slice of northeast Australia, Papua, New Guinea, southwest Japan and Korea, the moon will rise during totality on the evening of Dec. 21. Because of low altitude and bright evening twilight, observers in these locations may not see much of the moon at all until it begins to emerge from out of the Earth's shadow.
Conversely, much of the United Kingdom and parts of western and northern Europe will see the moon set during totality on the morning of Dec. 21. Because of low altitude and bright morning twilight, observers in these locations may not see much of the moon at all after it slips completely into the Earth's shadow.
Past and future
The last total lunar eclipse occurred on Feb. 20 to Feb. 21, 2008 and was visible from most of the Americas, as well as Europe, much of Africa and western Asia. In 2011, there will be two total lunar eclipses. The first, on June 15, will be visible primarily from the Eastern Hemisphere and will have an unusually long duration of totality lasting one hour and 40 minutes.
Another total lunar eclipse will occur on Dec. 10 and will be visible over the western half of North America before moonset. For the next total lunar eclipse that will be visible across all of North America, we must wait until April 14 to April 15, 2014.
Rare Event: Upcoming Full Moon To Align With Winter Solstice
From Space.com:
Rare Event: Upcoming Full Moon to Align With Solstice
By Joe Rao
SPACE.com Skywatching Columnist
posted: 17 December 2010
02:56 pm ET
The upcoming Dec. 21 full moon — besides distinguishing itself from the others in 2010 by undergoing a total eclipse — will also take place on the same date as the solstice (the winter solstice if you live north of the equator, and the summer solstice if you live to the south).
Winter solstice is the shortest day of the year in the Northern Hemisphere and marks the official beginning of winter. The sun is at its lowest in our sky because the North Pole of our tilted planet is pointing away from it.
So, how often does the December full moon coincide with the solstice? To answer this question, let's use Universal Time (UT), also sometimes referred to as Greenwich Mean Time (GMT). We do this because in answering this question, it's important to define a specific time zone.
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www.honda.comFor example, if you live in Honolulu, this December's full moon does not fall on the date of the solstice. Hawaii Time runs 10 hours behind GMT and the full moon occurs on Dec. 20 at 10:13 p.m. local time, while the solstice comes the following day at 1:38 p.m. Alaska, too, will have the full moon and the solstice occur on these respective dates, but in a time zone one hour later than Hawaii.
But both the full moon and solstice do occur on the same date (Dec. 21) in Greenwich, as well across the contiguous United States and Canada.
Prior to this year, there were solstice full moons in 1999 (Dec. 22) and 1980 (Dec. 21).
Interestingly, after this year, we'll have a long time to wait until we have a December full moon occur on the same date as the solstice: Dec. 21, 2094! And even more interesting – just like this year – that same full moon will fall into Earth's shadow in a total lunar eclipse. However, unlike this year, the 2094 eclipse will not be visible from the Western Hemisphere, but will be able to be seen from Europe, Africa and much of Asia. [How to Watch the Dec. 20 Total Lunar Eclipse]
Finally, this raises the question — prior to 2010, when was the last time that we had a total lunar eclipse occur on the same calendar date as the winter solstice? The answer, incredibly, takes us back nearly four centuries.
On Dec. 21, 1638, the full moon was in total eclipse from 1:12 to 2:47 UT. And the solstice occurred later in the day at 16:05 UT. [Amazing photos of a total lunar eclipse]
Once again, it's important to note that this occurred at the Greenwich meridian. For the Americas, this eclipse actually occurred during the evening of Dec. 20, while the solstice occurred on the following day.
Rare Event: Upcoming Full Moon to Align With Solstice
By Joe Rao
SPACE.com Skywatching Columnist
posted: 17 December 2010
02:56 pm ET
The upcoming Dec. 21 full moon — besides distinguishing itself from the others in 2010 by undergoing a total eclipse — will also take place on the same date as the solstice (the winter solstice if you live north of the equator, and the summer solstice if you live to the south).
Winter solstice is the shortest day of the year in the Northern Hemisphere and marks the official beginning of winter. The sun is at its lowest in our sky because the North Pole of our tilted planet is pointing away from it.
So, how often does the December full moon coincide with the solstice? To answer this question, let's use Universal Time (UT), also sometimes referred to as Greenwich Mean Time (GMT). We do this because in answering this question, it's important to define a specific time zone.
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www.honda.comFor example, if you live in Honolulu, this December's full moon does not fall on the date of the solstice. Hawaii Time runs 10 hours behind GMT and the full moon occurs on Dec. 20 at 10:13 p.m. local time, while the solstice comes the following day at 1:38 p.m. Alaska, too, will have the full moon and the solstice occur on these respective dates, but in a time zone one hour later than Hawaii.
But both the full moon and solstice do occur on the same date (Dec. 21) in Greenwich, as well across the contiguous United States and Canada.
Prior to this year, there were solstice full moons in 1999 (Dec. 22) and 1980 (Dec. 21).
Interestingly, after this year, we'll have a long time to wait until we have a December full moon occur on the same date as the solstice: Dec. 21, 2094! And even more interesting – just like this year – that same full moon will fall into Earth's shadow in a total lunar eclipse. However, unlike this year, the 2094 eclipse will not be visible from the Western Hemisphere, but will be able to be seen from Europe, Africa and much of Asia. [How to Watch the Dec. 20 Total Lunar Eclipse]
Finally, this raises the question — prior to 2010, when was the last time that we had a total lunar eclipse occur on the same calendar date as the winter solstice? The answer, incredibly, takes us back nearly four centuries.
On Dec. 21, 1638, the full moon was in total eclipse from 1:12 to 2:47 UT. And the solstice occurred later in the day at 16:05 UT. [Amazing photos of a total lunar eclipse]
Once again, it's important to note that this occurred at the Greenwich meridian. For the Americas, this eclipse actually occurred during the evening of Dec. 20, while the solstice occurred on the following day.
Wednesday, December 15, 2010
How To Watch The 20 December Total Lunar Eclipse
From Space.com:
How to Watch the Dec. 20 Total Lunar Eclipse
By Geoff Gaherty
Starry Night Education
posted: 15 December 2010
02:16 pm ET
A total lunar eclipse set to take place next Monday night and Tuesday morning (Dec. 20-21) will be well-placed for observers across North America to catch a view.
On the East Coast, it begins half an hour after midnight on Tuesday; on the West Coast, it begins around 9:30 p.m. PST Monday. In all cases, the whole eclipse will be observable before the moon sets in the west just as the sun is rising in the east. Maximum eclipse is at 3:17 a.m. EST/12:17 a.m. PST.
During a total lunar eclipse, the Earth gets between the full moon and the sun, blocking the sun's light from bouncing off the lunar surface. Although lunar eclipses occur fairly frequently, usually at the rate of about two a year, they often hold surprises.
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www.webcrawler.comNo one knows until the eclipse actually occurs how deep it will be and what color the moon will show. This is determined by weather conditions around the Earth's rim at the time of the eclipse, as the sun's light is colored and refracted inward by thousands of sunsets and sunrises.
If the air is clear around the rim of the Earth, the eclipse may be quite light; if cloudy, quite dark. Again, depending on those sunrises and sunsets, the moon may appear orange, red, dark brown or slate gray.
This star chart shows where in the sky the upcoming lunar eclipse will appear. And check this NASA lunar eclipse chart to see how visible the eclipse will be from different regions around the world.
Astronomers often try to estimate the magnitude, or brightness, of the eclipsed moon. Because the moon is much larger in apparent diameter than the stars and planets, it's necessary to "shrink" the moon to make comparisons more accurate. One way to do this is to view the moon through binoculars the wrong way around, looking in the objective end. Another way is to view it in a reflecting garden globe.
It is fun to repeat the observations made by early Greek astronomers of the curve of the Earth's shadow on the moon's face, which they used to prove that the Earth was round. Greek astronomers also used the curve of the Earth's shadow to calculate the relative sizes of the Earth and moon.
One thing worth observing is how different the shadow of the Earth falling on the moon looks compared to the regular phases of the moon observed every month during the year. There's a common folk belief that the moon's phases are caused by the shadow of the Earth falling on the moon, rather than by the sun illuminating the spherical globe of the moon from different angles.
The moon's shadow during an eclipse is much less curved than the lunar terminator, and always concave. The Earth's shadow is strongly colored by light refracted through the Earth's atmosphere, while the normal lunar terminator is colorless.
One special object to look for in this eclipse is the open star cluster Messier 35 in the constellation Gemini. This will be just three degrees above the eclipsed moon, half a binocular field away. It's also interesting to see how many faint stars you can see when the moon is fully eclipsed — you will see far more than are visible against the bright full moon before and after the eclipse.
A lunar eclipse makes for many photo opportunities.
Be sure to bracket your exposures (try different exposures longer and shorter than what your meter says) because a bright moon in a dark sky often fools cameras' exposure meters. If you normally keep a filter on your lens for protection, take it off to photograph the eclipse; otherwise, you may spoil your pictures with a ghost image of the moon. And use a telephoto lens or maximum zoom: The moon always looks larger to the eye than it does on film. Be sure to take some wide-angle shots as the moon gets lower in the sky toward the end of the eclipse.
How to Watch the Dec. 20 Total Lunar Eclipse
By Geoff Gaherty
Starry Night Education
posted: 15 December 2010
02:16 pm ET
A total lunar eclipse set to take place next Monday night and Tuesday morning (Dec. 20-21) will be well-placed for observers across North America to catch a view.
On the East Coast, it begins half an hour after midnight on Tuesday; on the West Coast, it begins around 9:30 p.m. PST Monday. In all cases, the whole eclipse will be observable before the moon sets in the west just as the sun is rising in the east. Maximum eclipse is at 3:17 a.m. EST/12:17 a.m. PST.
During a total lunar eclipse, the Earth gets between the full moon and the sun, blocking the sun's light from bouncing off the lunar surface. Although lunar eclipses occur fairly frequently, usually at the rate of about two a year, they often hold surprises.
Ads by GoogleYour Zodiac HoroscopeInsert Your Birthdate & Get Answers about Past-Present and Future. Free
AboutAstro.com/zodiacYouTube's Best of 2010Most watched videos of the year, top music videos and more…
www.youtube.com/rewindMoon Eclipse Video ClipSearch multiple engines for moon eclipse video clip
www.webcrawler.comNo one knows until the eclipse actually occurs how deep it will be and what color the moon will show. This is determined by weather conditions around the Earth's rim at the time of the eclipse, as the sun's light is colored and refracted inward by thousands of sunsets and sunrises.
If the air is clear around the rim of the Earth, the eclipse may be quite light; if cloudy, quite dark. Again, depending on those sunrises and sunsets, the moon may appear orange, red, dark brown or slate gray.
This star chart shows where in the sky the upcoming lunar eclipse will appear. And check this NASA lunar eclipse chart to see how visible the eclipse will be from different regions around the world.
Astronomers often try to estimate the magnitude, or brightness, of the eclipsed moon. Because the moon is much larger in apparent diameter than the stars and planets, it's necessary to "shrink" the moon to make comparisons more accurate. One way to do this is to view the moon through binoculars the wrong way around, looking in the objective end. Another way is to view it in a reflecting garden globe.
It is fun to repeat the observations made by early Greek astronomers of the curve of the Earth's shadow on the moon's face, which they used to prove that the Earth was round. Greek astronomers also used the curve of the Earth's shadow to calculate the relative sizes of the Earth and moon.
One thing worth observing is how different the shadow of the Earth falling on the moon looks compared to the regular phases of the moon observed every month during the year. There's a common folk belief that the moon's phases are caused by the shadow of the Earth falling on the moon, rather than by the sun illuminating the spherical globe of the moon from different angles.
The moon's shadow during an eclipse is much less curved than the lunar terminator, and always concave. The Earth's shadow is strongly colored by light refracted through the Earth's atmosphere, while the normal lunar terminator is colorless.
One special object to look for in this eclipse is the open star cluster Messier 35 in the constellation Gemini. This will be just three degrees above the eclipsed moon, half a binocular field away. It's also interesting to see how many faint stars you can see when the moon is fully eclipsed — you will see far more than are visible against the bright full moon before and after the eclipse.
A lunar eclipse makes for many photo opportunities.
Be sure to bracket your exposures (try different exposures longer and shorter than what your meter says) because a bright moon in a dark sky often fools cameras' exposure meters. If you normally keep a filter on your lens for protection, take it off to photograph the eclipse; otherwise, you may spoil your pictures with a ghost image of the moon. And use a telephoto lens or maximum zoom: The moon always looks larger to the eye than it does on film. Be sure to take some wide-angle shots as the moon gets lower in the sky toward the end of the eclipse.
Giant Stealth Planet May Explain Rain Of Comets From Solar System's Edge
From Space.com:
Giant Stealth Planet May Explain Rain of Comets from Solar System's Edge
By Charles Q. Choi
SPACE.com Contributor
posted: 01 December 2010
06:56 am ET
Our sun may have a companion that disturbs comets from the edge of the solar system — a giant planet with up to four times the mass of Jupiter, researchers suggest.
A NASA space telescope launched last year may soon detect such a stealth companion to our sun, if it actually exists, in the distant icy realm of the comet-birthing Oort cloud, which surrounds our solar system with billions of icy objects.
The potential jumbo Jupiter would likely be a world so frigid it is difficult to spot, researchers said. It could be found up to 30,000 astronomical units from the sun. One AU is the distance between the Earth and the sun, about 93 million miles (150 million km).
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wallpapers.smileycentral.comMost systems with stars like our sun — so-called class G stars — possess companions. Only one-third are single-star systems like our solar system.
Not a nemesis
Scientists have already proposed that a hidden star, which they call "Nemesis," might lurk a light-year or so away from our sun. They suggest that during its orbit, this red dwarf or brown dwarf star would regularly enter the Oort cloud, jostling the orbits of many comets there and causing some to fall toward Earth. That would provide an explanation for what seems to be a cycle of mass extinctions here.
Still, other astronomers recently found that if Nemesis did exist, its orbit could not be nearly as stable as claimed.
Now researchers point to evidence that our sun might have a different sort of companion.
To avoid confusion with the Nemesis model, astrophysicists John Matese and Daniel Whitmire at the University of Louisiana at Lafayette dub their conjectured object "Tyche" — the good sister of the goddess Nemesis in Greek mythology, and a name proposed by scientists working on NASA's Wide-Field Infrared Survey Explorer (WISE) space telescope.
It is the WISE observatory that, using its all-seeing infrared eye, stands the best chance of having spotted Tyche, if this companion to the sun exists at all, the researchers said. [WISE telescope's amazing images]
Matese and Whitmire detailed their research Nov. 17 online edition of the journal Icarus.
Comet-flinging sun companion
The researchers noted that most comets that fly into the inner solar system seem to come from the outer region of the Oort cloud. Their calculations suggest the gravitational influence of a planet one to four times the mass of Jupiter in this area might be responsible.
Two centuries of observations have indicated an anomaly that suggests the existence of Tyche, Matese said. "The probability that it could be caused by a statistical fluke has remained very small," he added.
The pull of Tyche might also explain why the dwarf planet Sedna has such an unusually elongated orbit, the researchers added.
If Tyche existed, it would probably be very cold, roughly minus 100 degrees F (-73 degrees C), they said, which could explain why it has escaped detection for so long — its coldness means that it would not radiate any heat scientists could easily spot, and its distance from any star means it would not reflect much light.
"Most planetary scientists would not be surprised if the largest undiscovered companion was Neptune-sized or smaller, but a Jupiter-mass object would be a surprise," Matese told SPACE.com. "If the conjecture is indeed true, the important implications would relate to how it got there — touching on the early solar environment — and how it might have affected the subsequent distributions of comets and, to a lesser extent, the known planets."
Is Tyche really out there?
The fact of Tyche's existence is questionable, since the pattern seen in the outer Oort cloud is not seen in the inner Oort.
"Conventional wisdom says that the patterns should tend to correlate, and they don't," Matese said.
If the WISE team was lucky, it caught evidence for the Tyche solar companion twice before the space observatory's original mission ended in October. That could be enough to corroborate the object's existence within a few months as researchers analyze WISE's data.
But if WISE detected signs of Tyche only once (or not at all), researchers would have to wait years for other telescopes to confirm or deny the potential solar companion's existence, Matese said.
Giant Stealth Planet May Explain Rain of Comets from Solar System's Edge
By Charles Q. Choi
SPACE.com Contributor
posted: 01 December 2010
06:56 am ET
Our sun may have a companion that disturbs comets from the edge of the solar system — a giant planet with up to four times the mass of Jupiter, researchers suggest.
A NASA space telescope launched last year may soon detect such a stealth companion to our sun, if it actually exists, in the distant icy realm of the comet-birthing Oort cloud, which surrounds our solar system with billions of icy objects.
The potential jumbo Jupiter would likely be a world so frigid it is difficult to spot, researchers said. It could be found up to 30,000 astronomical units from the sun. One AU is the distance between the Earth and the sun, about 93 million miles (150 million km).
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wallpapers.smileycentral.comMost systems with stars like our sun — so-called class G stars — possess companions. Only one-third are single-star systems like our solar system.
Not a nemesis
Scientists have already proposed that a hidden star, which they call "Nemesis," might lurk a light-year or so away from our sun. They suggest that during its orbit, this red dwarf or brown dwarf star would regularly enter the Oort cloud, jostling the orbits of many comets there and causing some to fall toward Earth. That would provide an explanation for what seems to be a cycle of mass extinctions here.
Still, other astronomers recently found that if Nemesis did exist, its orbit could not be nearly as stable as claimed.
Now researchers point to evidence that our sun might have a different sort of companion.
To avoid confusion with the Nemesis model, astrophysicists John Matese and Daniel Whitmire at the University of Louisiana at Lafayette dub their conjectured object "Tyche" — the good sister of the goddess Nemesis in Greek mythology, and a name proposed by scientists working on NASA's Wide-Field Infrared Survey Explorer (WISE) space telescope.
It is the WISE observatory that, using its all-seeing infrared eye, stands the best chance of having spotted Tyche, if this companion to the sun exists at all, the researchers said. [WISE telescope's amazing images]
Matese and Whitmire detailed their research Nov. 17 online edition of the journal Icarus.
Comet-flinging sun companion
The researchers noted that most comets that fly into the inner solar system seem to come from the outer region of the Oort cloud. Their calculations suggest the gravitational influence of a planet one to four times the mass of Jupiter in this area might be responsible.
Two centuries of observations have indicated an anomaly that suggests the existence of Tyche, Matese said. "The probability that it could be caused by a statistical fluke has remained very small," he added.
The pull of Tyche might also explain why the dwarf planet Sedna has such an unusually elongated orbit, the researchers added.
If Tyche existed, it would probably be very cold, roughly minus 100 degrees F (-73 degrees C), they said, which could explain why it has escaped detection for so long — its coldness means that it would not radiate any heat scientists could easily spot, and its distance from any star means it would not reflect much light.
"Most planetary scientists would not be surprised if the largest undiscovered companion was Neptune-sized or smaller, but a Jupiter-mass object would be a surprise," Matese told SPACE.com. "If the conjecture is indeed true, the important implications would relate to how it got there — touching on the early solar environment — and how it might have affected the subsequent distributions of comets and, to a lesser extent, the known planets."
Is Tyche really out there?
The fact of Tyche's existence is questionable, since the pattern seen in the outer Oort cloud is not seen in the inner Oort.
"Conventional wisdom says that the patterns should tend to correlate, and they don't," Matese said.
If the WISE team was lucky, it caught evidence for the Tyche solar companion twice before the space observatory's original mission ended in October. That could be enough to corroborate the object's existence within a few months as researchers analyze WISE's data.
But if WISE detected signs of Tyche only once (or not at all), researchers would have to wait years for other telescopes to confirm or deny the potential solar companion's existence, Matese said.
Friday, December 10, 2010
Gemenids To Shower Meteor "Gems" On Skywatchers Next Week
From Space.com:
Geminids to Shower Meteor 'Gems' on Skywatchers Next Week
By Joe Rao
SPACE.com Skywatching Columnist
posted: 10 December 2010
03:02 pm ET
November's Leonid meteor shower may have passed us by, but that doesn't mean there aren't any good meteor displays to look forward to as the end of 2010 draws near. In fact, one of the best is just around the corner, scheduled to reach its peak next week: the Geminid meteor shower.
The Geminids get their name from the constellation of Gemini, the Twins, where the display of so-called "shooting stars" appears to originate from the night sky. During the overnight hours of Dec. 13 and Dec. 14, the night of this shower's peak, the meteors should appear to emanate from a spot in the sky near the bright star Castor in Gemini.
This sky map shows where to look for the Geminid meteor shower when it peaks on Dec. 13 and Dec. 14.
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wallpapers.smileycentral.comDecember's meteor gems
The Geminid meteors are — for those willing to brave the chill of a December night — a fine winter shower, and usually the most satisfying of all the annual showers. They can even surpass the famous Perseid meteors of August at their peak.
Studies of past displays show that this shower has a reputation for being rich in slow, bright, graceful meteors and fireballs as well as faint meteors, with relatively fewer objects of medium brightness. Many appear yellowish in hue. Some even seem to form jagged or divided paths.
According to the late meteor specialist Neil Bone, at 2 grams per cubic centimeter (0.07 pounds per cubic inch) on average, Geminid meteoroids are several times denser than the cometary dust flakes that supply most meteor showers. Add this to the relatively slow speed with which Geminids typically encounter Earth — about 22 miles (35 km) per second — about half the speed of a Leonid meteor, and you have a recipe for meteors that linger a bit longer in view than most.
The Earth moves quickly through this meteor stream. The rate of meteors increases steadily for two or three days before maximum, reaching roughly above a quarter of its peak strength, then drops off sharply, lasting for only about a day afterward.
Those late Geminids, however, tend to be especially bright. A few renegade forerunners and late stragglers might be seen for a week or more before and after the peak night. One interesting finding made recently from video analysis by the International Meteor Organization was that Geminids have been detected as early as Nov. 30 — totally unexpected from past visual observations.
Some lunar Interference
The Geminids usually perform splendidly every year, although as was the case for last month's Leonids, the moon is going to pose a bit of a problem this time. In fact, the moon will reach first quarter phase on Dec. 13, the same night as the Geminid peak, shining brightly in the dim constellation of Pisces, the Fishes. That means that many of the fainter Geminid streaks will likely be washed out by the bright moonlight.
But unlike the Leonids, where the moon was brightly illuminating the sky most of the night, in the case of the Geminids the moon will be setting around 12:30 a.m. (your local time) early on Tuesday, Dec. 14. That means that the sky will be dark and moonless for the balance of the night, making for perfect viewing conditions for the shower.
Perfect timing!
In addition, according to Margaret Campbell-Brown and Peter Brown in the 2010 Observer's Handbook of the Royal Astronomical Society of Canada, peak activity is projected to occur at or near 6 a.m. EST on Dec. 14.
Under normal conditions on the night of maximum activity, with ideal dark-sky conditions, at least 60 to 120 Geminid meteors can be expected to burst across the sky every hour on average (light pollution greatly cuts these numbers). So, in 2010, along with a lack of significant moonlight, North Americans are projected to be the best situated to catch the very crest of the shower, when the hourly rates conceivably could exceed 120!
British meteor astronomer Alastair McBeath also points out that a new detailed analysis confirms that Geminid near-peak activity is very persistent with hourly rates of around 80 to 130 often seen for almost a day around the predicted time of maximum, corresponding this year from about 1900 UT on Dec. 13 to 1600 UT on Dec. 14. So from virtually anywhere on Earth, an excellent Geminid show can be anticipated.
Bundle up!
A productive Geminid watch can actually begin as early as 10 p.m. local time, because the shower's radiant (where the meteors appear to originate from) is already fairly high in the eastern sky by then. Even with that annoyingly bright moon still high in the western sky, it will be worth watching for some early "Gems."
But keep this in mind: At this time of year, meteor watching can be a long, cold business. You wait and you wait for meteors to appear. When they don't appear right away, and if you're cold and uncomfortable, you're not going to be looking for meteors for very long. Therefore, make sure you're warm and comfortable.
Warm cocoa or coffee brought along in a thermos can take the edge off the chill, as well as provide a slight stimulus. It's even better if you can observe with friends. That way, you can keep each other awake, as well as cover more sky. Give your eyes time to adapt to the dark before starting.
Debris from a dead comet?
The Geminids will be especially noticeable right after the moon sets, as their radiant point will be passing nearly overhead. The higher a shower's radiant, the more meteors it produces all over the sky.
The track of each meteor does not necessarily begin near Castor, or even in the constellation Gemini, but it always turns out that the path of a Geminid extended backward along the direction of flight passes through a tiny region of sky about 0.2 degrees in diameter (an effect of perspective). In apparent size, that's less than half the width of the moon.
As such, this is a rather sharply defined radiant as meteor showers go, suggesting the stream is "young" — perhaps only several thousand years old.
Geminids stand apart from the other meteor showers in that they seem to have been spawned not by a comet, but by 3200 Phaeton, an Earth-crossing asteroid. Then again, the Geminids may be comet debris after all, for some astronomers consider Phaeton to be the dead nucleus of a burned-out comet that somehow got trapped into an unusually tight orbit.
Geminids to Shower Meteor 'Gems' on Skywatchers Next Week
By Joe Rao
SPACE.com Skywatching Columnist
posted: 10 December 2010
03:02 pm ET
November's Leonid meteor shower may have passed us by, but that doesn't mean there aren't any good meteor displays to look forward to as the end of 2010 draws near. In fact, one of the best is just around the corner, scheduled to reach its peak next week: the Geminid meteor shower.
The Geminids get their name from the constellation of Gemini, the Twins, where the display of so-called "shooting stars" appears to originate from the night sky. During the overnight hours of Dec. 13 and Dec. 14, the night of this shower's peak, the meteors should appear to emanate from a spot in the sky near the bright star Castor in Gemini.
This sky map shows where to look for the Geminid meteor shower when it peaks on Dec. 13 and Dec. 14.
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wallpapers.smileycentral.comDecember's meteor gems
The Geminid meteors are — for those willing to brave the chill of a December night — a fine winter shower, and usually the most satisfying of all the annual showers. They can even surpass the famous Perseid meteors of August at their peak.
Studies of past displays show that this shower has a reputation for being rich in slow, bright, graceful meteors and fireballs as well as faint meteors, with relatively fewer objects of medium brightness. Many appear yellowish in hue. Some even seem to form jagged or divided paths.
According to the late meteor specialist Neil Bone, at 2 grams per cubic centimeter (0.07 pounds per cubic inch) on average, Geminid meteoroids are several times denser than the cometary dust flakes that supply most meteor showers. Add this to the relatively slow speed with which Geminids typically encounter Earth — about 22 miles (35 km) per second — about half the speed of a Leonid meteor, and you have a recipe for meteors that linger a bit longer in view than most.
The Earth moves quickly through this meteor stream. The rate of meteors increases steadily for two or three days before maximum, reaching roughly above a quarter of its peak strength, then drops off sharply, lasting for only about a day afterward.
Those late Geminids, however, tend to be especially bright. A few renegade forerunners and late stragglers might be seen for a week or more before and after the peak night. One interesting finding made recently from video analysis by the International Meteor Organization was that Geminids have been detected as early as Nov. 30 — totally unexpected from past visual observations.
Some lunar Interference
The Geminids usually perform splendidly every year, although as was the case for last month's Leonids, the moon is going to pose a bit of a problem this time. In fact, the moon will reach first quarter phase on Dec. 13, the same night as the Geminid peak, shining brightly in the dim constellation of Pisces, the Fishes. That means that many of the fainter Geminid streaks will likely be washed out by the bright moonlight.
But unlike the Leonids, where the moon was brightly illuminating the sky most of the night, in the case of the Geminids the moon will be setting around 12:30 a.m. (your local time) early on Tuesday, Dec. 14. That means that the sky will be dark and moonless for the balance of the night, making for perfect viewing conditions for the shower.
Perfect timing!
In addition, according to Margaret Campbell-Brown and Peter Brown in the 2010 Observer's Handbook of the Royal Astronomical Society of Canada, peak activity is projected to occur at or near 6 a.m. EST on Dec. 14.
Under normal conditions on the night of maximum activity, with ideal dark-sky conditions, at least 60 to 120 Geminid meteors can be expected to burst across the sky every hour on average (light pollution greatly cuts these numbers). So, in 2010, along with a lack of significant moonlight, North Americans are projected to be the best situated to catch the very crest of the shower, when the hourly rates conceivably could exceed 120!
British meteor astronomer Alastair McBeath also points out that a new detailed analysis confirms that Geminid near-peak activity is very persistent with hourly rates of around 80 to 130 often seen for almost a day around the predicted time of maximum, corresponding this year from about 1900 UT on Dec. 13 to 1600 UT on Dec. 14. So from virtually anywhere on Earth, an excellent Geminid show can be anticipated.
Bundle up!
A productive Geminid watch can actually begin as early as 10 p.m. local time, because the shower's radiant (where the meteors appear to originate from) is already fairly high in the eastern sky by then. Even with that annoyingly bright moon still high in the western sky, it will be worth watching for some early "Gems."
But keep this in mind: At this time of year, meteor watching can be a long, cold business. You wait and you wait for meteors to appear. When they don't appear right away, and if you're cold and uncomfortable, you're not going to be looking for meteors for very long. Therefore, make sure you're warm and comfortable.
Warm cocoa or coffee brought along in a thermos can take the edge off the chill, as well as provide a slight stimulus. It's even better if you can observe with friends. That way, you can keep each other awake, as well as cover more sky. Give your eyes time to adapt to the dark before starting.
Debris from a dead comet?
The Geminids will be especially noticeable right after the moon sets, as their radiant point will be passing nearly overhead. The higher a shower's radiant, the more meteors it produces all over the sky.
The track of each meteor does not necessarily begin near Castor, or even in the constellation Gemini, but it always turns out that the path of a Geminid extended backward along the direction of flight passes through a tiny region of sky about 0.2 degrees in diameter (an effect of perspective). In apparent size, that's less than half the width of the moon.
As such, this is a rather sharply defined radiant as meteor showers go, suggesting the stream is "young" — perhaps only several thousand years old.
Geminids stand apart from the other meteor showers in that they seem to have been spawned not by a comet, but by 3200 Phaeton, an Earth-crossing asteroid. Then again, the Geminids may be comet debris after all, for some astronomers consider Phaeton to be the dead nucleus of a burned-out comet that somehow got trapped into an unusually tight orbit.
Thursday, December 2, 2010
Senators Vow To Enforce NASA Authorization Act
From Space.com:
Senators Vow To Enforce NASA Authorization Act
By Amy Svitak
Space News
posted: 01 December 2010
05:55 pm ET
WASHINGTON — U.S. lawmakers accused the administration of U.S. President Barack Obama of trying to undermine legislation directing NASA to develop a heavy-lift rocket while continuing work on a deep-space capsule and said they intend to see to it that the law is followed.
During the nearly two-hour-long hearing Dec. 1, Sen. Bill Nelson (D-Fla.) and fellow members of the Senate Commerce, Science and Transportation Committee sought assurance that NASA intends to carry out the NASA Authorization Act of 2010 the president signed into law Oct. 11, despite fiscal uncertainties the agency faces in the absence of a 2011 appropriations bill.
"We passed it, the president signed it into law, and now we want that law implemented," even if NASA is forced to continue operating at 2010 spending levels as part of a stopgap measure Congress is likely to approve this month, Nelson said. Known as a continuing resolution, the temporary appropriation would hold NASA spending rates to levels consistent with the $18.74 billion Congress approved for the agency last year, a figure that is just 1.67 percent shy of the $19 billion lawmakers authorized for NASA in 2011. "We want to see this law implemented without a lot of griping and moaning and groaning if we're able to get that kind of appropriation," said Nelson, chairman of the panel's science and space subcommittee.
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www.healthcare.govRecalling what he characterized as "misstatements" and "sometimes mischief" on the part of Obama administration officials before Congress approved the authorization bill in September, Nelson said he is concerned NASA is putting off plans to initiate development of a new space launch system as directed in the law. Specifically, the bill authorizes $3 billion next year for continued work on a multipurpose crew capsule based on NASA's Orion Crew Exploration Vehicle and development of a new heavy-lift rocket with core elements capable of delivering between 70-100 metric tons to orbit by the end of 2016.
In remarks following the hearing, Nelson declined to name names, but said there were attempts by "certain people within the administration" to prevent the authorization measure's passage in both the Senate and U.S. House. [NASA in Transition]
"I want to make sure that those elements in the administration who were trying to have their way, instead of the way that is the law, that they're not going to undermine this law," Nelson said.
NASA Chief Financial Officer Elizabeth Robinson, who testified during the hearing, said the agency is eager to carry out elements of the authorization act. But she said NASA is prevented in some cases by restrictions in the continuing resolution under which the agency currently operates. Those restrictions, she said, include a prohibition on canceling NASA's Constellation program, a five-year-old effort to replace the space shuttle fleet with Orion and the Ares family of rockets optimized for lunar missions.
"While work with exploration may begin to address the provisions of the authorization act, the [continuing resolution] restrictions maintain prohibitions on program element terminations within the Constellation Program, which may eventually limit application of funding needed for key exploration activities," Robinson said in prepared testimony.
Sen. David Vitter (R-La.) accused the Obama administration of using language in the 2010 appropriations act for NASA and upheld in the continuing resolution to delay work on the new space launch system mandated in the authorization act.
"I'm not saying that language is irrelevant, but I really think it's largely an excuse," Vitter said. "The irony is pretty clear. Before this new authorization bill the administration was doing absolutely everything it could administratively to shut down Constellation programs. Now after the new authorization bill has passed, the administration is pointing to that language saying we can't possibly end Constellation and stop those programs."
Vitter said Congress is already working on new language that could be inserted into a continuing resolution or omnibus spending package for 2011 that would remove such impediments, adding that he is "committed to working on anything we need to work on legislatively to clear away any remaining hurdles like the language from last year's appropriations bill."
Nelson also asked whether NASA plans to carry out an additional flight of the space shuttle next year as authorized in the new law.
Robinson said the agency plans to conduct the additional flight to the International Space Station.
"The only caveat I would put forth is we still don't have a final appropriations [act], so we don't know if we have the money to carry it out," she said. "We're trying to quantify what it means to hedge our bets in case there's a drastic change in funding level, but we have every intention of moving forward on that."
Nelson asked Robinson what programs might suffer if NASA is forced to continue operating under the stopgap spending measure through the end of 2011, which would leave the agency $276 million short of the $19 billion Congress authorized for 2011.
"The [NASA] administrator has already considered that and he decided that the best place to take that money would be the 21st century launch initiative for 2011," she said, referring to $429 million authorized over several years that would pay for upgrades at NASA's Kennedy Space Center in Nelson's home state. "It would be difficult at this point once we get clearance to actually obligate all that money so we wanted to take the reduction there with the thought that we would take it up later."
Senators Vow To Enforce NASA Authorization Act
By Amy Svitak
Space News
posted: 01 December 2010
05:55 pm ET
WASHINGTON — U.S. lawmakers accused the administration of U.S. President Barack Obama of trying to undermine legislation directing NASA to develop a heavy-lift rocket while continuing work on a deep-space capsule and said they intend to see to it that the law is followed.
During the nearly two-hour-long hearing Dec. 1, Sen. Bill Nelson (D-Fla.) and fellow members of the Senate Commerce, Science and Transportation Committee sought assurance that NASA intends to carry out the NASA Authorization Act of 2010 the president signed into law Oct. 11, despite fiscal uncertainties the agency faces in the absence of a 2011 appropriations bill.
"We passed it, the president signed it into law, and now we want that law implemented," even if NASA is forced to continue operating at 2010 spending levels as part of a stopgap measure Congress is likely to approve this month, Nelson said. Known as a continuing resolution, the temporary appropriation would hold NASA spending rates to levels consistent with the $18.74 billion Congress approved for the agency last year, a figure that is just 1.67 percent shy of the $19 billion lawmakers authorized for NASA in 2011. "We want to see this law implemented without a lot of griping and moaning and groaning if we're able to get that kind of appropriation," said Nelson, chairman of the panel's science and space subcommittee.
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www.healthcare.govRecalling what he characterized as "misstatements" and "sometimes mischief" on the part of Obama administration officials before Congress approved the authorization bill in September, Nelson said he is concerned NASA is putting off plans to initiate development of a new space launch system as directed in the law. Specifically, the bill authorizes $3 billion next year for continued work on a multipurpose crew capsule based on NASA's Orion Crew Exploration Vehicle and development of a new heavy-lift rocket with core elements capable of delivering between 70-100 metric tons to orbit by the end of 2016.
In remarks following the hearing, Nelson declined to name names, but said there were attempts by "certain people within the administration" to prevent the authorization measure's passage in both the Senate and U.S. House. [NASA in Transition]
"I want to make sure that those elements in the administration who were trying to have their way, instead of the way that is the law, that they're not going to undermine this law," Nelson said.
NASA Chief Financial Officer Elizabeth Robinson, who testified during the hearing, said the agency is eager to carry out elements of the authorization act. But she said NASA is prevented in some cases by restrictions in the continuing resolution under which the agency currently operates. Those restrictions, she said, include a prohibition on canceling NASA's Constellation program, a five-year-old effort to replace the space shuttle fleet with Orion and the Ares family of rockets optimized for lunar missions.
"While work with exploration may begin to address the provisions of the authorization act, the [continuing resolution] restrictions maintain prohibitions on program element terminations within the Constellation Program, which may eventually limit application of funding needed for key exploration activities," Robinson said in prepared testimony.
Sen. David Vitter (R-La.) accused the Obama administration of using language in the 2010 appropriations act for NASA and upheld in the continuing resolution to delay work on the new space launch system mandated in the authorization act.
"I'm not saying that language is irrelevant, but I really think it's largely an excuse," Vitter said. "The irony is pretty clear. Before this new authorization bill the administration was doing absolutely everything it could administratively to shut down Constellation programs. Now after the new authorization bill has passed, the administration is pointing to that language saying we can't possibly end Constellation and stop those programs."
Vitter said Congress is already working on new language that could be inserted into a continuing resolution or omnibus spending package for 2011 that would remove such impediments, adding that he is "committed to working on anything we need to work on legislatively to clear away any remaining hurdles like the language from last year's appropriations bill."
Nelson also asked whether NASA plans to carry out an additional flight of the space shuttle next year as authorized in the new law.
Robinson said the agency plans to conduct the additional flight to the International Space Station.
"The only caveat I would put forth is we still don't have a final appropriations [act], so we don't know if we have the money to carry it out," she said. "We're trying to quantify what it means to hedge our bets in case there's a drastic change in funding level, but we have every intention of moving forward on that."
Nelson asked Robinson what programs might suffer if NASA is forced to continue operating under the stopgap spending measure through the end of 2011, which would leave the agency $276 million short of the $19 billion Congress authorized for 2011.
"The [NASA] administrator has already considered that and he decided that the best place to take that money would be the 21st century launch initiative for 2011," she said, referring to $429 million authorized over several years that would pay for upgrades at NASA's Kennedy Space Center in Nelson's home state. "It would be difficult at this point once we get clearance to actually obligate all that money so we wanted to take the reduction there with the thought that we would take it up later."
Thursday, November 25, 2010
Monday, November 22, 2010
Sea Of Constellations Visible For Northern Hemisphere Sky-Watchers
From Space.com:
Sea of Constellations Visible For Northern Hemisphere Skywatchers
By Joe Rao
SPACE.com Skywatching Columnist
posted: 22 November 2010
05:44 pm ET
The traditional constellations of autumn in the Northern Hemisphere have returned to the evening sky and bring with them a rich body of lore and mythology — though their stars are rather faint.
Several of these constellations are dwelling in the celestial "sea" – that is, they are of a watery nature.
These constellations include Capricornus, the sea goat; Aquarius, the water carrier; Pisces, the fishes; Piscis Austrinus, the southern fish; Cetus, the sea monster; and Eridanus, the river. They are appearing this week in the southern part of the evening sky at around 8 p.m. local time in northern latitudes.
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wallpapers.smileycentral.comThis sky map shows the constellations of the southern sky in the Northern Hemisphere this week.
The first three constellations mentioned here form part of the zodiac;w all members of this group have been associated with the rainy season of ancient Mideast lands.
There is also a mythological connection between these star pictures and an ancient great flood in the Tigris-Euphrates basin, which has sometimes been linked to the Deluge in Genesis. Here's a tour of these water-themed constellations in the night sky:
Grotesque sea goat
Probably because the ancients knew very little about marine life, it is not surprising that they populated the deep with every manner of monster, including what we now call mermaids. Capricornus, the sea goat, now leaning down in the southwest sky, is one of those odd land-sea animal hybrids the ancients were wont to create.
It traces back to the Mesopotamian period. According to folklore, there were some sea nymphs and goddesses playing in a field one day when the mischievous god, Pan, saw them and joined in the fun. In order to amuse them, he transformed himself into a goat and leaped into the river. Instantly, the part of his body that was submerged in the water was turned into a fish while the part out of the water remained a goat.
Zeus, who just happened to be passing by, saw Pan's feat and was so amused that he decreed the perpetuation of this grotesque figure in our night sky. Although Capricornus is a goat, in the sky it looks more like a roughly triangular figure which may suggest an inverted cocked hat, perhaps a bird flying toward you, or even a boat.
Once, I pointed it out to a friend of mine who remarked that (in keeping with the watery aspect) it looked "like the south end of a bikini."
Watery tale
The rich mythology of Aquarius, the water carrier, which hovers above and to the left of Capricornus, is very ancient, tracing back to the earliest civilizations in the Tigris and Euphrates valleys.
In fact, on some of their cylinder seals they pictured these rivers as pouring out from Aquarius' water jar. The ancient Egyptians had an equally picturesque image of this constellation that they associated with the Nile's annual flooding, which, far from being disastrous, added a new layer each year to the valley's fertile soil.
The Egyptians believed the flooding was caused by Aquarius dipping his water jar into the river to refill it. Quite a number of Aquarius' stars have proper names. The names Sadalmelik, Sadalsuud[s1] , Sadachbia, and Albali all indicate in Arabic that these are "lucky" stars astrologically. "Skat" means the lower foot in Arabic, while "ancha" comes from Medieval Latin and refers to the upper thigh or hip.
One fish, two fish
Were it not one of the 12 zodiacal signs, Pisces the fishes would not be deemed important at all.
Astronomers measure star brightness in terms of magnitude — the smaller the number (close to or less than one), the brighter the object. None of the stars in Pisces shine brighter than fourth magnitude – though brilliant Jupiter currently resides here – but the constellation does display a striking, though not bright, pattern now high in the southern sky.
It also has some historical affinities, including one related to Christmas.
To the early Israelites, Pisces was a sacred part of the sky. Planetary gatherings or other occurrences of astrological significance were regarded as harbingers of important events if they happened there.
For example, a favorite explanation of the Star of Bethlehem is a planetary grouping involving Mars, Jupiter and Saturn that took place in Pisces in 6 B.C.
The main legend to account for the Fishes is that Cupid and Venus – the god and goddess of love – escape the monster Typhon by jumping into a river and assuming a piscine form.
Long-necked bird and a southern fish
In addition to the six groupings I mentioned earlier, we might also include the constellation of Grus, the Crane, among the watery constellations, for this wading bird often inhabits swampy and marshy terrain.
It currently lies low near the southwest horizon. With its two second-magnitude stars marking the bottom of a distinctive inverted Y-shaped pattern, and with third-magnitude Gamma at the top, Grus is actually a prominent fall constellation for viewers in the tropics and the Southern Hemisphere.
Directly above Grus is Piscis Austrinus, the southern fish, which has the only first- magnitude star – Fomalhaut – in this whole collection of watery constellations.
Aside from Jupiter — which this year happens to be glowing brilliantly nearby in Pisces — Fomalhaut usually appears as a solitary star in a very dull and unexciting region of the sky.
Indeed, Fomalhaut is the only "true" first magnitude star of autumn. It's a white star, only about twice as large as the sun and about 14 times as bright. It appears prominent to us because it is only 25 light-years away.
Godzilla-fish?
East of Aquarius and south of Pisces is Cetus, a sea monster who in mythology was sent by the god Neptune to devour the princess Andromeda.
This constellation is often called the Whale, but in the allegorical pictures found in many of the old star atlases it usually appears very un-whale-like (almost like Godzilla with a fish tail!).
However, today we identify the scientific name for the whale order is Cetacea, and the study of whales is known as Cetacean Zoology; hence the name Cetus identifies this constellation as a whale.
Lazy celestial river
Lastly, now coming into view low in the southeast is a large, albeit faint and shapeless constellation known as the Celestial River, Eridanus.
It starts near the brilliant bluish-white star Rigel in Orion then flows southwestward just like a river would: a winding stream of dim stars whose meanderings wind all the way down to below the southern horizon. Unfortunately, stargazers in much of the United States never get to see the very end of the river, for it ends in a blaze of splendor.
The bluish star Achernar glows at the end of the river, ninth-brightest star in the sky, yet so far south that only those who live near and along the Gulf Coast (Florida, New Orleans, south Texas), get a glimpse of it, poking a short distance above the horizon.
Also in Eridanus is Epsilon Eridani, the third-nearest star visible to the unaided eye.
Located at a distance of just 10.8 light years from Earth, Epsilon has about one-third of the luminosity of our sun and is about 90 percent as large. Thus, here is a star that is reasonably comparable to our own sun.
Welcome to Astronomy: Getting StartedTelescopes For BeginnersTelescopes Up! A Guide to the Night Sky's New Stargazing SeasonJoe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York.
Sea of Constellations Visible For Northern Hemisphere Skywatchers
By Joe Rao
SPACE.com Skywatching Columnist
posted: 22 November 2010
05:44 pm ET
The traditional constellations of autumn in the Northern Hemisphere have returned to the evening sky and bring with them a rich body of lore and mythology — though their stars are rather faint.
Several of these constellations are dwelling in the celestial "sea" – that is, they are of a watery nature.
These constellations include Capricornus, the sea goat; Aquarius, the water carrier; Pisces, the fishes; Piscis Austrinus, the southern fish; Cetus, the sea monster; and Eridanus, the river. They are appearing this week in the southern part of the evening sky at around 8 p.m. local time in northern latitudes.
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wallpapers.smileycentral.comThis sky map shows the constellations of the southern sky in the Northern Hemisphere this week.
The first three constellations mentioned here form part of the zodiac;w all members of this group have been associated with the rainy season of ancient Mideast lands.
There is also a mythological connection between these star pictures and an ancient great flood in the Tigris-Euphrates basin, which has sometimes been linked to the Deluge in Genesis. Here's a tour of these water-themed constellations in the night sky:
Grotesque sea goat
Probably because the ancients knew very little about marine life, it is not surprising that they populated the deep with every manner of monster, including what we now call mermaids. Capricornus, the sea goat, now leaning down in the southwest sky, is one of those odd land-sea animal hybrids the ancients were wont to create.
It traces back to the Mesopotamian period. According to folklore, there were some sea nymphs and goddesses playing in a field one day when the mischievous god, Pan, saw them and joined in the fun. In order to amuse them, he transformed himself into a goat and leaped into the river. Instantly, the part of his body that was submerged in the water was turned into a fish while the part out of the water remained a goat.
Zeus, who just happened to be passing by, saw Pan's feat and was so amused that he decreed the perpetuation of this grotesque figure in our night sky. Although Capricornus is a goat, in the sky it looks more like a roughly triangular figure which may suggest an inverted cocked hat, perhaps a bird flying toward you, or even a boat.
Once, I pointed it out to a friend of mine who remarked that (in keeping with the watery aspect) it looked "like the south end of a bikini."
Watery tale
The rich mythology of Aquarius, the water carrier, which hovers above and to the left of Capricornus, is very ancient, tracing back to the earliest civilizations in the Tigris and Euphrates valleys.
In fact, on some of their cylinder seals they pictured these rivers as pouring out from Aquarius' water jar. The ancient Egyptians had an equally picturesque image of this constellation that they associated with the Nile's annual flooding, which, far from being disastrous, added a new layer each year to the valley's fertile soil.
The Egyptians believed the flooding was caused by Aquarius dipping his water jar into the river to refill it. Quite a number of Aquarius' stars have proper names. The names Sadalmelik, Sadalsuud[s1] , Sadachbia, and Albali all indicate in Arabic that these are "lucky" stars astrologically. "Skat" means the lower foot in Arabic, while "ancha" comes from Medieval Latin and refers to the upper thigh or hip.
One fish, two fish
Were it not one of the 12 zodiacal signs, Pisces the fishes would not be deemed important at all.
Astronomers measure star brightness in terms of magnitude — the smaller the number (close to or less than one), the brighter the object. None of the stars in Pisces shine brighter than fourth magnitude – though brilliant Jupiter currently resides here – but the constellation does display a striking, though not bright, pattern now high in the southern sky.
It also has some historical affinities, including one related to Christmas.
To the early Israelites, Pisces was a sacred part of the sky. Planetary gatherings or other occurrences of astrological significance were regarded as harbingers of important events if they happened there.
For example, a favorite explanation of the Star of Bethlehem is a planetary grouping involving Mars, Jupiter and Saturn that took place in Pisces in 6 B.C.
The main legend to account for the Fishes is that Cupid and Venus – the god and goddess of love – escape the monster Typhon by jumping into a river and assuming a piscine form.
Long-necked bird and a southern fish
In addition to the six groupings I mentioned earlier, we might also include the constellation of Grus, the Crane, among the watery constellations, for this wading bird often inhabits swampy and marshy terrain.
It currently lies low near the southwest horizon. With its two second-magnitude stars marking the bottom of a distinctive inverted Y-shaped pattern, and with third-magnitude Gamma at the top, Grus is actually a prominent fall constellation for viewers in the tropics and the Southern Hemisphere.
Directly above Grus is Piscis Austrinus, the southern fish, which has the only first- magnitude star – Fomalhaut – in this whole collection of watery constellations.
Aside from Jupiter — which this year happens to be glowing brilliantly nearby in Pisces — Fomalhaut usually appears as a solitary star in a very dull and unexciting region of the sky.
Indeed, Fomalhaut is the only "true" first magnitude star of autumn. It's a white star, only about twice as large as the sun and about 14 times as bright. It appears prominent to us because it is only 25 light-years away.
Godzilla-fish?
East of Aquarius and south of Pisces is Cetus, a sea monster who in mythology was sent by the god Neptune to devour the princess Andromeda.
This constellation is often called the Whale, but in the allegorical pictures found in many of the old star atlases it usually appears very un-whale-like (almost like Godzilla with a fish tail!).
However, today we identify the scientific name for the whale order is Cetacea, and the study of whales is known as Cetacean Zoology; hence the name Cetus identifies this constellation as a whale.
Lazy celestial river
Lastly, now coming into view low in the southeast is a large, albeit faint and shapeless constellation known as the Celestial River, Eridanus.
It starts near the brilliant bluish-white star Rigel in Orion then flows southwestward just like a river would: a winding stream of dim stars whose meanderings wind all the way down to below the southern horizon. Unfortunately, stargazers in much of the United States never get to see the very end of the river, for it ends in a blaze of splendor.
The bluish star Achernar glows at the end of the river, ninth-brightest star in the sky, yet so far south that only those who live near and along the Gulf Coast (Florida, New Orleans, south Texas), get a glimpse of it, poking a short distance above the horizon.
Also in Eridanus is Epsilon Eridani, the third-nearest star visible to the unaided eye.
Located at a distance of just 10.8 light years from Earth, Epsilon has about one-third of the luminosity of our sun and is about 90 percent as large. Thus, here is a star that is reasonably comparable to our own sun.
Welcome to Astronomy: Getting StartedTelescopes For BeginnersTelescopes Up! A Guide to the Night Sky's New Stargazing SeasonJoe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, New York.
Sunday, November 21, 2010
The Really Strange Story Behind Sunday's Blue Moon
From Space.com and Yahoo News:
The Really Strange Story Behind Sunday's Blue Moon
SPACE.com Skywatching Columnist
SPACE.com joe Rao
space.com Skywatching Columnist
space.com – Fri Nov 19, 4:15 pm ET
The full moon of November arrives on Sunday and will bring with it a cosmic addition: It will also be a so-called "blue moon."
"But wait a minute," you might ask. "Isn't a 'blue moon' defined as the second full moon that occurs during a calendar month? Sunday's full moon falls on Nov. 21 and it will be the only full moon in November 2010. So how can it be a 'blue' moon?"
Indeed, November's full moon is blue moon – but only if we follow a rule that's now somewhat obscure.
In fact, the current "two- full moons in one month" rule has superseded an older rule that would allow us to call Sunday's moon "blue." To be clear, the moon does not actually appear a blue color during a blue moon, it has to do with lunar mechanics.
Confused yet?
Well, as the late Paul Harvey used to say — here now, is the rest of the story:
The blue moon rule
Back in the July 1943 issue of Sky & Telescope magazine, in a question and answer column written by Lawrence J. Lafleur, there was a reference made to the term "blue moon." [Gallery - Full Moon Fever]
Lafleur cited the unusual term from a copy of the 1937 edition of the now-defunct Maine Farmers' Almanac (NOT to be confused with The Farmers' Almanac of Lewiston, Maine, which is still in business).
On the almanac page for August 1937, the calendrical meaning for the term "blue moon" was given.
That explanation said that the moon "... usually comes full twelve times in a year, three times for each season."
Occasionally, however, there will come a year when there are 13 full moons during a year, not the usual 12. The almanac explanation continued:
"This was considered a very unfortunate circumstance, especially by the monks who had charge of the calendar of thirteen months for that year, and it upset the regular arrangement of church festivals. For this reason thirteen came to be considered an unlucky number."
And with that extra full moon, it also meant that one of the four seasons would contain four full moons instead of the usual three.
"There are seven Blue Moons in a Lunar Cycle of nineteen years," continued the almanac, ending on the comment that, "In olden times the almanac makers had much difficulty calculating the occurrence of the Blue Moon and this uncertainty gave rise to the expression 'Once in a Blue Moon.'"
An unfortunate oversight
But while LaFleur quoted the almanac's account, he made one very important omission: He never specified the date for this particular blue moon.
As it turned out, in 1937, it occurred on Aug. 21. That was the third full moon in the summer of 1937, a summer season that would see a total of four full moons.
Names were assigned to each moon in a season: For example, the first moon of summer was called the early summer moon, the second was the midsummer moon, and the last was called the late summer moon.
But when a particular season has four moons, the third was apparently called a blue moon so that the fourth and final one can continue to be called the late moon.
So where did we get the "two full moons in a month rule" that is so popular today?
A moon mistake
Once again, we must turn to the pages of Sky & Telescope.
This time, on page 3 of the March 1946 issue, James Hugh Pruett wrote an article, "Once in a Blue Moon," in which he made a reference to the term "blue moon" and referenced LaFleur's article from 1943.
But because Pruett had no specific full moon date for 1937 to fall back on, his interpretation of the ruling given by the Maine Farmers' Almanac was highly subjective. Pruett ultimately came to this conclusion:
"Seven times in 19 years there were – and still are – 13 full moons in a year. This gives 11 months with one full moon each and one with two. This second in a month, so I interpret it, was called Blue Moon."
How unfortunate that Pruett did not have a copy of that 1937 almanac at hand, or else he would have almost certainly noticed that his "two full moons in a single month assumption" would have been totally wrong.
For the blue moon date of Aug. 21 was most definitely not the second full moon that month!
Blue moon myth runs wild
Pruett's 1946 explanation was, of course, the wrong interpretation and it might have been completely forgotten were it not for Deborah Byrd who used it on her popular National Public Radio program, "StarDate" on Jan. 31, 1980.
We could almost say that in the aftermath of her radio show, the incorrect blue moon rule "went viral" — or at least the '80s equivalent of it.
Over the next decade, this new blue moon definition started appearing in diverse places, such as the World Almanac for Kids and the board game Trivial Pursuit.
I must confess here, that even I was involved in helping to perpetuate the new version of the blue moon phenomenon. Nearly 30 years ago, in the Dec. 1, 1982 edition of The New York Times, I made reference to it in that newspaper's "New York Day by Day" column.
And by 1988, the new definition started receiving international press coverage.
Today, Pruett's misinterpreted "two full moons in a month rule" is recognized worldwide. Indeed, Sky & Telescope turned a literary lemon into lemonade, proclaiming later that – however unintentional – it changed pop culture and the English language in unexpected ways.
Meanwhile, the original Maine Farmers' Almanac rule had been all but forgotten.
Playing by the (old) rules
Now, let's come back to this Sunday's full moon.
Under the old Almanac rule, this would technically be a blue moon. In the autumn season of 2010, there are four full moons:
Sept. 23
Oct. 22
Nov. 21
Dec. 21
"But wait," you might say. "Dec. 21 is the first day of winter."
And you would be correct, but only if you live north of the equator in the Northern Hemisphere. South of the equator it's the first day of summer.
In 2010, the solstice comes at 6:38 p.m. EST (2338 UT).
But the moon turns full at 3:13 a.m. EST (0813 UT). That's 15 hours and 25 minutes before the solstice occurs. So the Dec. 21 full moon occurs during the waning hours of fall and qualifies as the fourth full moon of the season.
This means that under the original Maine Almanac rule – the one promoted by Lafleur and later misinterpreted by Pruett – the third full moon of the 2010 fall season on Nov. 21 would be a blue moon.
Choose your blue moon
So what Blue Moon definition tickles your fancy? Is it the second full moon in a calendar month, or (as is the case on Sunday) the third full moon in a season with four?
Maybe it's both. The final decision is solely up to you.
Sunday's full moon will look no different than any other full moon. But the moon can change color in certain conditions.
After forest fires or volcanic eruptions, the moon can appear to take on a bluish or even lavender hue. Soot and ash particles, deposited high in the Earth's atmosphere, can sometimes make the moon appear bluish.
In the aftermath of the massive eruption of Mount Pinatubo in the Philippines in June 1991, there were reports of blue moons (and even blue suns) worldwide.
We could even call the next full moon (on Dec. 21) a "red moon," but for a different reason: On that day there will be a total eclipse of the moon and, for a short while, the moon will actually glow with a ruddy reddish hue.
More on that special event in the days to come here at SPACE.com, so stay tuned!
Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, N.Y.
The Really Strange Story Behind Sunday's Blue Moon
SPACE.com Skywatching Columnist
SPACE.com joe Rao
space.com Skywatching Columnist
space.com – Fri Nov 19, 4:15 pm ET
The full moon of November arrives on Sunday and will bring with it a cosmic addition: It will also be a so-called "blue moon."
"But wait a minute," you might ask. "Isn't a 'blue moon' defined as the second full moon that occurs during a calendar month? Sunday's full moon falls on Nov. 21 and it will be the only full moon in November 2010. So how can it be a 'blue' moon?"
Indeed, November's full moon is blue moon – but only if we follow a rule that's now somewhat obscure.
In fact, the current "two- full moons in one month" rule has superseded an older rule that would allow us to call Sunday's moon "blue." To be clear, the moon does not actually appear a blue color during a blue moon, it has to do with lunar mechanics.
Confused yet?
Well, as the late Paul Harvey used to say — here now, is the rest of the story:
The blue moon rule
Back in the July 1943 issue of Sky & Telescope magazine, in a question and answer column written by Lawrence J. Lafleur, there was a reference made to the term "blue moon." [Gallery - Full Moon Fever]
Lafleur cited the unusual term from a copy of the 1937 edition of the now-defunct Maine Farmers' Almanac (NOT to be confused with The Farmers' Almanac of Lewiston, Maine, which is still in business).
On the almanac page for August 1937, the calendrical meaning for the term "blue moon" was given.
That explanation said that the moon "... usually comes full twelve times in a year, three times for each season."
Occasionally, however, there will come a year when there are 13 full moons during a year, not the usual 12. The almanac explanation continued:
"This was considered a very unfortunate circumstance, especially by the monks who had charge of the calendar of thirteen months for that year, and it upset the regular arrangement of church festivals. For this reason thirteen came to be considered an unlucky number."
And with that extra full moon, it also meant that one of the four seasons would contain four full moons instead of the usual three.
"There are seven Blue Moons in a Lunar Cycle of nineteen years," continued the almanac, ending on the comment that, "In olden times the almanac makers had much difficulty calculating the occurrence of the Blue Moon and this uncertainty gave rise to the expression 'Once in a Blue Moon.'"
An unfortunate oversight
But while LaFleur quoted the almanac's account, he made one very important omission: He never specified the date for this particular blue moon.
As it turned out, in 1937, it occurred on Aug. 21. That was the third full moon in the summer of 1937, a summer season that would see a total of four full moons.
Names were assigned to each moon in a season: For example, the first moon of summer was called the early summer moon, the second was the midsummer moon, and the last was called the late summer moon.
But when a particular season has four moons, the third was apparently called a blue moon so that the fourth and final one can continue to be called the late moon.
So where did we get the "two full moons in a month rule" that is so popular today?
A moon mistake
Once again, we must turn to the pages of Sky & Telescope.
This time, on page 3 of the March 1946 issue, James Hugh Pruett wrote an article, "Once in a Blue Moon," in which he made a reference to the term "blue moon" and referenced LaFleur's article from 1943.
But because Pruett had no specific full moon date for 1937 to fall back on, his interpretation of the ruling given by the Maine Farmers' Almanac was highly subjective. Pruett ultimately came to this conclusion:
"Seven times in 19 years there were – and still are – 13 full moons in a year. This gives 11 months with one full moon each and one with two. This second in a month, so I interpret it, was called Blue Moon."
How unfortunate that Pruett did not have a copy of that 1937 almanac at hand, or else he would have almost certainly noticed that his "two full moons in a single month assumption" would have been totally wrong.
For the blue moon date of Aug. 21 was most definitely not the second full moon that month!
Blue moon myth runs wild
Pruett's 1946 explanation was, of course, the wrong interpretation and it might have been completely forgotten were it not for Deborah Byrd who used it on her popular National Public Radio program, "StarDate" on Jan. 31, 1980.
We could almost say that in the aftermath of her radio show, the incorrect blue moon rule "went viral" — or at least the '80s equivalent of it.
Over the next decade, this new blue moon definition started appearing in diverse places, such as the World Almanac for Kids and the board game Trivial Pursuit.
I must confess here, that even I was involved in helping to perpetuate the new version of the blue moon phenomenon. Nearly 30 years ago, in the Dec. 1, 1982 edition of The New York Times, I made reference to it in that newspaper's "New York Day by Day" column.
And by 1988, the new definition started receiving international press coverage.
Today, Pruett's misinterpreted "two full moons in a month rule" is recognized worldwide. Indeed, Sky & Telescope turned a literary lemon into lemonade, proclaiming later that – however unintentional – it changed pop culture and the English language in unexpected ways.
Meanwhile, the original Maine Farmers' Almanac rule had been all but forgotten.
Playing by the (old) rules
Now, let's come back to this Sunday's full moon.
Under the old Almanac rule, this would technically be a blue moon. In the autumn season of 2010, there are four full moons:
Sept. 23
Oct. 22
Nov. 21
Dec. 21
"But wait," you might say. "Dec. 21 is the first day of winter."
And you would be correct, but only if you live north of the equator in the Northern Hemisphere. South of the equator it's the first day of summer.
In 2010, the solstice comes at 6:38 p.m. EST (2338 UT).
But the moon turns full at 3:13 a.m. EST (0813 UT). That's 15 hours and 25 minutes before the solstice occurs. So the Dec. 21 full moon occurs during the waning hours of fall and qualifies as the fourth full moon of the season.
This means that under the original Maine Almanac rule – the one promoted by Lafleur and later misinterpreted by Pruett – the third full moon of the 2010 fall season on Nov. 21 would be a blue moon.
Choose your blue moon
So what Blue Moon definition tickles your fancy? Is it the second full moon in a calendar month, or (as is the case on Sunday) the third full moon in a season with four?
Maybe it's both. The final decision is solely up to you.
Sunday's full moon will look no different than any other full moon. But the moon can change color in certain conditions.
After forest fires or volcanic eruptions, the moon can appear to take on a bluish or even lavender hue. Soot and ash particles, deposited high in the Earth's atmosphere, can sometimes make the moon appear bluish.
In the aftermath of the massive eruption of Mount Pinatubo in the Philippines in June 1991, there were reports of blue moons (and even blue suns) worldwide.
We could even call the next full moon (on Dec. 21) a "red moon," but for a different reason: On that day there will be a total eclipse of the moon and, for a short while, the moon will actually glow with a ruddy reddish hue.
More on that special event in the days to come here at SPACE.com, so stay tuned!
Joe Rao serves as an instructor and guest lecturer at New York's Hayden Planetarium. He writes about astronomy for The New York Times and other publications, and he is also an on-camera meteorologist for News 12 Westchester, N.Y.
Wednesday, November 17, 2010
The Best Time To See The Leonid Meteor Showers Is Now
from Space.com and Yahoo News:
Best Time to See the Leonid Meteor Shower Is Now
AP – Leonids meteors are seen streaking through the sky in Muju county, 300 kilometers, southwest of Seoul, … . Slideshow:Leonid Meteor Shower . Play Video Space Video:Cosmonauts walk in space Reuters .
Tariq Malik
SPACE.com Managing Editor
SPACE.com tariq Malik
space.com Managing Editor
space.com – Wed Nov 17, 11:45 am ET
The Leonid meteor shower of 2010 is peaking this week and the best time to see the sky show is now.
The annual Leonids should be at their best through Nov. 18, according to skywatching experts. Avid meteor gazers graced with clear skies may see between 15 and 20 meteors per hour.
Skywatchers should look toward the constellation Leo in the eastern sky to see "shooting stars" from the Leonids, which appear to radiate out of the constellation. The best time to try to see the Leonids are in the last two or three hours before sunrise, when the moon has set.
Click image to see photos of past Leonid meteor showers
AP/Yonhap
A Leonids sky map posted here shows where to look in the predawn sky.
[Photos: New view of Earth from space station window]
"From the time of moonset until around 5:15 a.m. -- when the first streaks of dawn begin to appear in the east -- the sky will be dark and moonless," advises Joe Rao, SPACE.com skywatching columnist. "That interval will provide you with your best opportunity to see any Leonid meteors." [Gallery: Spectacular Leonid Meteor Shower Photos]
Another tip: Make sure to stay warm and get comfortable.
"If you have a lawn chair that reclines, use it during your search for Leonid meteors since it will help keep your neck from getting stiff as well as make it easier to look at the night sky," Rao said.
The Leonid meteor shower is an annual event that returns every mid-November. The shower is caused by material left behind the comet Tempel-Tuttle when it passes near Earth's orbit during its regular trip through the solar system. [Top 10 Leonid Meteor Shower Facts]
When the Earth passes through these knots of comet material, the gas and dust flares up in the atmosphere, creating spectacular meteors.
[Related: Plan to send astronauts on one-way mission to Mars]
Every 33 years, the Earth encounters a dense knot of material -- most recently in 2002 -- to create dazzling displays of shooting stars. During those showers, it can be possible to see hundreds or thousands of meteors per hour.
That isn't the case this year because the Earth is passing through a less dense area of Comet Tempel-Tuttle's trail, Rao said.
Still, the Leonids retain a reputation for offering impressive meteor displays.
But with fewer meteors expected this year, you may want to travel a bit to find the best spot. Meteor-gazing from a rooftop in suburbia doesn't always offer the best view.
"For your best view, get away from city lights. Look for state or city parks or other safe, dark sites," advise the editors of StarDate magazine at the McDonald Observatory in Texas. "Lie on a blanket or reclining chair to get a full-sky view. If you can see all of the stars in the Little Dipper, you have good dark-adapted vision."
Best Time to See the Leonid Meteor Shower Is Now
AP – Leonids meteors are seen streaking through the sky in Muju county, 300 kilometers, southwest of Seoul, … . Slideshow:Leonid Meteor Shower . Play Video Space Video:Cosmonauts walk in space Reuters .
Tariq Malik
SPACE.com Managing Editor
SPACE.com tariq Malik
space.com Managing Editor
space.com – Wed Nov 17, 11:45 am ET
The Leonid meteor shower of 2010 is peaking this week and the best time to see the sky show is now.
The annual Leonids should be at their best through Nov. 18, according to skywatching experts. Avid meteor gazers graced with clear skies may see between 15 and 20 meteors per hour.
Skywatchers should look toward the constellation Leo in the eastern sky to see "shooting stars" from the Leonids, which appear to radiate out of the constellation. The best time to try to see the Leonids are in the last two or three hours before sunrise, when the moon has set.
Click image to see photos of past Leonid meteor showers
AP/Yonhap
A Leonids sky map posted here shows where to look in the predawn sky.
[Photos: New view of Earth from space station window]
"From the time of moonset until around 5:15 a.m. -- when the first streaks of dawn begin to appear in the east -- the sky will be dark and moonless," advises Joe Rao, SPACE.com skywatching columnist. "That interval will provide you with your best opportunity to see any Leonid meteors." [Gallery: Spectacular Leonid Meteor Shower Photos]
Another tip: Make sure to stay warm and get comfortable.
"If you have a lawn chair that reclines, use it during your search for Leonid meteors since it will help keep your neck from getting stiff as well as make it easier to look at the night sky," Rao said.
The Leonid meteor shower is an annual event that returns every mid-November. The shower is caused by material left behind the comet Tempel-Tuttle when it passes near Earth's orbit during its regular trip through the solar system. [Top 10 Leonid Meteor Shower Facts]
When the Earth passes through these knots of comet material, the gas and dust flares up in the atmosphere, creating spectacular meteors.
[Related: Plan to send astronauts on one-way mission to Mars]
Every 33 years, the Earth encounters a dense knot of material -- most recently in 2002 -- to create dazzling displays of shooting stars. During those showers, it can be possible to see hundreds or thousands of meteors per hour.
That isn't the case this year because the Earth is passing through a less dense area of Comet Tempel-Tuttle's trail, Rao said.
Still, the Leonids retain a reputation for offering impressive meteor displays.
But with fewer meteors expected this year, you may want to travel a bit to find the best spot. Meteor-gazing from a rooftop in suburbia doesn't always offer the best view.
"For your best view, get away from city lights. Look for state or city parks or other safe, dark sites," advise the editors of StarDate magazine at the McDonald Observatory in Texas. "Lie on a blanket or reclining chair to get a full-sky view. If you can see all of the stars in the Little Dipper, you have good dark-adapted vision."
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