Earth--Day and Night Regions

Earth--Day and Night Regions

Planetary Positions

Thursday, November 25, 2010

Happy Thanksgiving

Monday, November 22, 2010

Sea Of Constellations Visible For Northern Hemisphere Sky-Watchers


Sea of Constellations Visible For Northern Hemisphere Skywatchers

By Joe Rao 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.

Ads by GoogleOrionspath.ComThe best sale of the season. 20% off on the first purchase.

www.theworldbeneath.comFree Space WallpapersGet Cool Space Desktop Wallpapers w Planets, Moons & Stars-Try Them Now

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.


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 and Yahoo News:

The full moon rises above the tree tops in Moreland Hills, Ohio on Wednesday, April 8, 2009. (AP Photo/Amy Sancetta)

The Really Strange Story Behind Sunday's Blue Moon Skywatching Columnist joe Rao Skywatching Columnist – 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, 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 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 Managing Editor tariq Malik Managing Editor – 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


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, 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."

Four Leonid meteors are seen streaking through ...

Leonid meteors are seen streaking across the ...

Colorful streaks of meteors are seen in the sky ...

Stars outnumber Leonid meteors lighting up the ...

Jordanians look at the desert sky during the ...

Montgomery, Ala., photographer and avid stargazer ...

Wednesday, November 10, 2010

Venus And Saturn Now Grace The Pre-Dawn Sky


Venus and Saturn Now Grace the Predawn Sky

By Geoff Gaherty

Starry Night Education

posted: 10 November 2010

07:09 am ET

Venus and Saturn, two bright planetary gems of the sky, had been hiding from skywatchers in recent months, but they have returned with flair just ahead of the rising sun.

In the complicated dance of the planets, both planets appear from Earth to have moved west of the sun and both are now "morning stars" in the predawn sky, weather permitting.

This sky map shows where to look to see Venus and Saturn in the early-morning hours.

Ads by GoogleThe Night Sky TonightAll About The Night Sky Tonight The Night Sky Tonight in One Site! Space WallpapersGet Cool Space Desktop Wallpapers w Planets, Moons & Stars-Try Them Now

wallpapers.smileycentral.comYour Zodiac HoroscopeInsert Your Birthdate & Get Answers about Past-Present and Future. Free the most avid watchers of the sky probably haven't seen either of these planets for a couple of months. Both have been hiding close to the sun in our sky, but in very different locations.

Venus passed between the Earth and the sun two weeks ago on Oct. 29, in what is called an "inferior conjunction" with the sun. [Gallery: Spectacular Venus Photos]

The planets rarely align exactly, but Venus was only 6 degrees south of the sun at that time — for all intents and purposes, totally lost in the sun's glare. For comparison, the width of your fist held at arm's length takes up about 10 degrees of the night sky.

Saturn is a different story. On Oct. 1, it passed almost behind the sun, in what is called a "superior conjunction." It was only 2 degrees north of the sun on that date.

How to see Venus and Saturn

To find Venus and Saturn, go out about half an hour before sunrise any day this week and look a bit south of east.

If your skies are clear, the most obvious thing you will see will be brilliant Venus low on the horizon. Through binoculars or a small telescope, Venus will appear as a tiny slender crescent, since it is still almost completely back-lit by the sun just below the horizon.

About 5 degrees (one binocular field) above Venus is the first-magnitude star Spica in the constellation Virgo. About 12 degrees (two binocular fields) above that is Saturn.

If Saturn looks a bit brighter than when you saw it last, you're not mistaken. Saturn's rings, which have been almost edge-on to the Earth for the last two years, are now starting to tilt toward the Earth, and this has a striking effect on the planet's brightness to the naked eye.

Saturn's rings through telescopes

If you have access to a small telescope, take a look at Saturn. Its magnificent rings have now opened up so that it looks its old self.

Skywatchers should also look for the moons nearby Saturn. Titan, Saturn's largest moon, is visible in even the smallest telescope, and four more moons can be seen with larger amateur telescopes: Rhea, Dione, Tethys and Iapetus. Use a planetarium program on your computer to identify them.

Both Spica and Saturn are of first-magnitude brightness, but noticeably dimmer than the star Arcturus in the east, and much dimmer than Venus.

Venus and Saturn will grace our morning sky for most of the winter months, but this week is your first chance to welcome them back.

Wednesday, November 3, 2010

After Elections, Critics Of Obama Regime's NASA Plan Likely To Take Over Two Key Committees


After Elections, Critics of Obama's NASA Plan Likely to Take Over 2 Key Committees

By Amy Klamper

Space News Staff Writer

posted: 03 November 2010

06:56 pm ET

WASHINGTON — The Nov. 2 elections that will put Republicans in charge of the U.S. House of Representatives in January likely means that two vocal critics of U.S. President Barack Obama's new direction for NASA will assume leadership of committees that oversee the space agency.

Riding a wave of voter unhappiness due in part to the country's stalled economic recovery, Republican challengers as of early Nov. 3 had gained at least 60 seats in the House, well above the 39 needed to seize the majority of the chamber's 435 voting members.

Before the elections, Republican leaders pledged to curtail U.S. federal spending, which could also have implications for NASA.

Ads by GoogleObama 's Home RefinanceRefinance Rates as Lows as 3.48% See Free Low Rates- No Credit Check

Refinance.LoanReduce.comFree Space WallpapersGet Cool Space Desktop Wallpapers w Planets, Moons & Stars-Try Them Now

wallpapers.smileycentral.comBarack ObamaLove Him, Hate Him? What's Your Opinion? Vote Now. U.S. Senate is expected to remain under Democratic control, although Republicans made gains there as well. [Poll: Weigh in on NASA's New Direction]

Reps. Frank Wolf (R-Va.) and Ralph Hall (R-Texas), who both won re-election and are expected to assume leadership of key NASA oversight committees, have criticized Obama's plans to cancel the nation's Moon program and outsource crew transit to and from low Earth orbit.

Wolf, the ranking member of the powerful House Appropriations commerce, justice, science subcommittee, which oversees NASA spending, is expected to assume the panel's chairmanship come January. A staunch critic of the Obama plan, Wolf, who is entering his 16th term in Congress, has said the president's vision effectively would cede U.S. leadership in space.

"We would turn over the American space program to allow China to catch us," Wolf said shortly after the White House sent lawmakers a new NASA budget blueprint in February.

Commercial space plans under scrutiny

In addition to questioning Obama's plan to delay development of new rockets and spacecraft capable of taking astronauts into deep space, Wolf took issue with a plan to foster development of commercial crew taxis for operations in-low Earth orbit.

In an April 20 interview Wolf said private space firms could have "a role to bring cargo back and forth" between Earth and the International Space Station, but singled out one of two firms building new hardware for such missions — Hawthorne, Calif.-based Space Exploration Technologies (SpaceX) — as not having "the best record in the world." The other company, Dulles, Va.-based Orbital Sciences Corp., is located in Wolf's Virginia district.

Part of a growing number of House and Senate lawmakers who sought to strike a balance between the White House plan and concerns it could jeopardize U.S. leadership in space exploration, Wolf ultimately supported a Senate measure authorizing $58 billion for NASA over three years.

The bill, S. 3729, which Obama signed into law Oct. 11, retained elements of the president's commercial crew initiative while directing NASA to begin work on a heavy-lift rocket in 2011 — some five years earlier than the White House had envisioned.

The bill, brought to the House floor Sept. 29 under a rule suspension that prevented amendments and limited debate, won backing from 185 Democrats and 119 Republicans, including Hall, the ranking member of the House Science and Technology Committee that oversees NASA policy and which sets overall funding levels for congressional appropriators to consider.

Hall, who is expected to assume the committee's chairmanship next year, initially supported a House version of the authorization bill that would have gutted funding for Obama's commercial crew initiative. But in remarks made shortly before the House adopted the Senate compromise, Hall characterized the measure as flawed but necessary in order to move NASA forward.

"While the bill before us today is far from perfect, it offers clear direction for a NASA that's floundering," he


NASA in limbo

However, until Congress funds the newly enacted law in a forthcoming 2011 appropriations bill, the agency is likely to remain in limbo. [NASA in Transition]

Although lawmakers are expected to reconvene for a lame-duck session Nov. 15, it remains unclear whether new spending legislation will be approved before a stopgap measure intended to keep the government running into the current budget year expires Dec. 3. That stopgap measure, called a continuing resolution, funds the federal government at 2010 levels.

In the meantime, with incoming Republican leaders threatening to dial back discretionary spending across the federal government next year, the $19 billion Congress authorized for NASA in 2011 could be in jeopardy.

House Minority Leader Rep. John Boehner (R-Ohio), who is expected to become speaker of the House in January, voted against the recently enacted NASA legislation and more broadly has pledged to roll back spending in an effort to reduce the federal deficit.

In a weekly Republican address Oct. 30, Boehner criticized spending under Democratic leadership and outlined reforms in the governing agenda Republicans expect to implement in the 112th Congress.

"We're ready to cut spending to pre-'stimulus,' pre-bailout levels, saving taxpayers $100 billion almost immediately," Boehner said. "And we're ready to put in place strict budget caps that limit spending from here on out, to ensure that Washington is no longer on this spending binge."