Trio Of Planets To Be Visible Together

From Space.com:

Check It Out: Planetary Triangle Forming in the Evening Sky


By Geoff Gaherty

Starry Night Education

posted: 28 July 2010

10:00 am ET

A trio of planets converging in the night sky this week and for several nights will give casual skywatchers the perfect chance to easily see and identify worlds they might not normally notice. The event, building up to a super celestial snuggle in early August, is also a chance to watch and grasp orbital mechanics in action.



Venus, Mars and Saturn will gradually, night after night, move into a tight triangular grouping in the early evening sky. (This graphic shows where to look to spot the planetary triangle on Aug. 5.)



Venus is so bright, you can't miss it, and that will allow you to locate the other two worlds with no trouble. You can start watching the spectacle tonight. [Venus photos from around the world.]

Ads by GoogleFree 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

AboutAstro.com/horoscopeThe ancients believed planetary alignments to be full of mystery portending dreadful events. Now we realize that, because the planets all move in a common plane called the ecliptic, they regularly line up with each other over time as seen from planet Earth.

The ecliptic is the same path across the sky followed by the sun, and so the three planets will appear to be following the sun into the Western horizon as darkness falls.

The ecliptic corresponds to the plane in space that Earth and the other planets travel in as the orbit the sun. Since the inner planets, like Venus, make their annual orbits faster than the outer worlds, like Mars, they're constantly trading places in our sky, converging and receding from one another as seen from our vantage point.

Planetary alignments are known to astronomers as conjunctions or appulses. The moon, which is also traveling close to the plane the planets orbit in, is in conjunction with each of the planets at some point every month. Conjunctions between pairs of planets, particularly the faster moving inner planets, occur several times a year.

Conjunctions of three or more planets are much rarer. This one has been building for several months, and will reach its culmination in the coming week.

What you'll see

Look in the western sky just after sunset any night this week. Your eyes will immediately be drawn to the brilliant planet Venus – it's brighter than any night sky object except the moon.

Look more closely as the sky gets darker, and you will see that Venus is accompanied by two lesser lights. These are the planets Mars and Saturn.

On Saturday night, July 31, Mars will be just below Saturn, less than two degrees away (your fist on an outstretched arm measures about 10 degrees of the sky). The following Saturday, Aug. 7, Venus will have moved westward so that it is less than three degrees below Saturn.

All three planets are moving eastward (left to right for viewers in the Northern Hemisphere) against the background stars of the constellation Virgo. The solar system's inner planets move across our sky (and around the sun) in much less time much than the outer planets, and so they rapidly move past distant Saturn.

On Thursday night, Aug. 5, the three planets will be closest together, forming a tight triangle that will easily fit in the field of binoculars.

Appearances are deceptive. Although close together in the sky, the three planets are actually at very different distances from the Earth.

Venus is closest at 0.796 astronomical units distance, Mars next at 2.022 astronomical units, and Saturn a distant 10.191 astronomical units. Because distances to other planets are, well, astronomical if measured in miles or kilometers, astronomers usually measure them in astronomical units: an astronomical unit is the average distance between the Earth and the Sun, 93 million miles or 150 million kilometers.

Summer Meteor Shower Viewing Season In Full Swing

From Space.com:

Summer Meteor Shower Season in Full Swing


By Joe Rao

SPACE.com Skywatching Columnist

posted: 23 July 2010

09:16 am ET



For skywatchers in the Northern Hemisphere, late summer is usually regarded as the prime "meteor-viewing season," with one of the best displays of the year reaching its peak in mid-August. But some lesser-known summer meteor displays can still dazzle.



The summer meteor shower season hits its peak with the annual Perseid meteor shower, which is usually beloved by everyone from meteor enthusiasts to summer campers in August. This year will be an excellent one for the Perseids, as their peak will nearly coincide with a new moon, which should offer dark skies for prospective observers.



But the Perseids aren't the only meteor show in town. [Stunning meteor shower photos.]



Ads by GoogleTake the RealAge TestMillions have already taken this amazing test. What's your RealAge?

RealAge.comCoffee Fool BannedGrocery stores won't stock us because we're the truth on fresh!

www.CoffeeFool.comMeteor shower basics



In general, the Earth encounters richer meteoric activity during the second half of every year. And skywatchers are more likely to see twice as many meteors per hour in the predawn hours as compared to the evening hours.



This is due to the fact that during the pre-midnight hours we are on the "trailing" side of the Earth, due to our orbital motion through space. So any meteoric particle generally must have an orbital velocity greater than that of the Earth to "catch" us.



However, after midnight when we are turned onto the Earth's "leading" side, any particle that lies along the Earth's orbital path will enter our atmosphere as a meteor. As such objects collide with our atmosphere at speeds of 7 to 45 miles per second, their energy of motion rapidly dissipates in the form of heat, light, and ionization, creating short-lived streaks of light popularly referred to as "shooting stars."



Summertime meteors, occasionally flitting across your line of sight are especially noticeable between mid-July and the third week of August. And between Aug. 3 and 15, there are no fewer than six different minor displays that are active. These six are listed in the accompanying table [see table in sidebar].



The only equipment you'll need is clear weather, your eyes and a modest amount of patience.



What you might see



The actual number of meteors a single observer can see in an hour depends strongly on sky conditions. The rates given in the table are based on a limited star magnitude of +6.5 (considered to be the faintest star visible to the naked eye without the use of binoculars or a telescope; a really good sky!), an experienced observer, and an assumption that the radiant is directly overhead.



The radiant is the place in the sky where the paths of shower members, if extended backward, would intersect when plotted on a star chart. Your clinched fist held at arm's length is equal to roughly 10 degrees on the sky.



So if the radiant is 30 degrees (about three fists in size) above the horizon, the hourly rate is halved. At 15 degrees it is one-third.



While the hourly rates from these other meteor streams provide but a fraction of the numbers produced by the Perseids, combined, overall they provide a wide variety of meteors of differing colors, speeds and trajectories.



Among these are the Southern Delta Aquarids, which can produce faint, medium-speed meteors; the Alpha Capricornids, described as "slow, bright, long-trailed yellowish meteors" and the Kappa Cygnids which are classified as "slow moving and sometimes producing brilliant flaring fireballs." As such, if you stay out and watch long enough, you may be nicely rewarded for your time spent.



Note that five of the six showers listed, come from the region around the constellations of Aquarius and Capricornus. These constellations are highest in the southern sky between roughly 1 and 3 a.m. local daylight time. The Kappa Cygnids appear to emanate from the constellation Cygnus, which will appear more or less overhead within an hour of local midnight.



Moon muscles in



Currently the one drawback in watching for meteors is the moon, which will reach full phase on July 25. Since it will be in the sky practically the entire night, the brilliant light of July's full moon will likely obscure all but the very brightest streaks.



But in the nights that follow, the moon will be rising progressively later in the night as well as waning in phase and brightness. After Aug. 3, the moon will have diminished to a crescent phase and will become significantly less of a hindrance to viewers.

Neptune Hit By Comet 200 Years Ago

From Space.com:

Comet Smacked Neptune 200 Years Ago, Data Suggests


By Denise Chow

SPACE.com Staff Writer

posted: 23 July 2010

02:48 pm ET

New measurements of Neptune's atmosphere by a European space telescope suggest that a comet may have crashed into the gas giant about 200 years ago.



Scientists analyzed the composition of Neptune's atmosphere using data from the Herschel space observatory. They found a peculiar distribution of carbon monoxide in the gas giant's atmosphere, which could be an indication of an earlier comet impact.



The research is detailed in the July 16 online issue of the journal Astronomy & Astrophysics.



Ads by GoogleTake the RealAge TestMillions have already taken this amazing test. What's your RealAge?

RealAge.comYour Zodiac HoroscopeInsert Your Birthdate & Get Answers about Past-Present and Future. Free

AboutAstro.com/horoscopeFree Space WallpapersGet Cool Space Desktop Wallpapers w Planets, Moons & Stars-Try Them Now

wallpapers.smileycentral.comUsing past knowledge



Other similar collisions between comets (or asteroids) and planets helped the astronomers detect the telltale signs of cometary impacts. [Photos: Jupiter Hit By Asteroid or Comet]



When pieces of the comet Shoemaker-Levy 9 slammed into Jupiter in 1994, scientists were able to examine the trajectory and debris to better understand planetary impacts. Instruments aboard the space probes Voyager 2, Galileo and Ulysses also documented every detail of the rare incident.



The data now helps scientists detect the telltale signs of cometary impacts that happened many years ago. Comets, which are sometimes described as "dusty snowballs," leave their mark in the atmospheres of gas giants like Jupiter and Neptune in the form of water, carbon dioxide, carbon monoxide, hydrocyanic acid and carbon sulfide. Trace molecules of these compounds can be detected in the radiation emitted by the planets into space.



In February, scientists from the Max Planck Institute for Solar System Research (MPS) presented strong evidence for a comet impact on Saturn about 230 years ago. That study was published in the February 2010 issue of Astronomy & Astrophysics.



Neptune as well?



New measurements performed by the Photodetector Array Camera and Spectrometer (PACS) instrument aboard Herschel allowed astronomers to analyze the long-wave infrared radiation of Neptune. These observations indicate that Neptune may have experienced a similar cosmic collision.



The scientists examined the atmosphere of Neptune, which mainly consists of hydrogen and helium with traces of water, carbon dioxide and carbon monoxide. They detected an unusual distribution of carbon monoxide in Neptune's atmosphere, with much higher concentrations in the upper layer, called the stratosphere, compared to the troposphere layer beneath.



"The higher concentration of carbon monoxide in the stratosphere can only be explained by an external origin," said Paul Hartogh, a scientist at MPS and principle investigator of the Herschel science program that examines water and related chemistry in the solar system. "Normally, the concentrations of carbon monoxide in troposphere and stratosphere should be the same or decrease with increasing height."



A cometary impact would explain such curious results. The collision forces the comet to fall apart, while the carbon monoxide trapped in the comet's ice is released and distributed throughout the stratosphere over the years.



"From the distribution of carbon monoxide we can therefore derive the approximate time, when the impact took place," said Thibault Cavalie, also from MPS. This would help scientists confirm that a comet hit Neptune around 200 years ago, the researchers added.



The new study also appears to disprove a previous theory that tried to explain the strange distribution of carbon monoxide in Neptune's atmosphere. The older theory suggested that a constant flux of tiny dust particles from space introduces carbon monoxide into the gas giant's atmosphere.



But, in Neptune's stratosphere, the scientists also found a higher concentration of methane than expected.



What's methane got to do with it?



On Neptune, methane operates in similar ways to water vapor on Earth: the temperature of the tropopause – a barrier of colder air that separates the troposphere and stratosphere – determines how much water vapor can rise into the stratosphere.



If this barrier becomes warmer, more gas is able to pass through. On Earth, the temperature of the tropopause never falls beneath minus 176 degrees Fahrenheit (minus 80 degrees Celsius). On Neptune, however, the tropopause's mean temperature is minus 426 degrees Fahrenheit (minus 219 degrees Celsius).



This means that a gap in the barrier of the tropopause is the likely culprit for the elevated concentration of methane on Neptune.



At minus 415 degrees Fahrenheit (minus 213 degrees Celsius), the atmosphere at Neptune's southern pole is six degrees warmer than everywhere else, which allows gas to pass more easily from troposphere to stratosphere. The methane, which scientists think originates from the planet itself, can therefore spread throughout the stratosphere.



The European Space Agency (ESA) launched the Herschel infrared space telescope in May 2009. The observatory is the largest, most powerful infrared telescope in orbit today.

One Small Step For Man, 41 Years Later

From Michelle Malkin:

One Small Step For Man, 41 Years Later


By Doug Powers • July 20, 2010 09:00 PM **Written by Doug Powers



Today is the 41st anniversary of the Apollo 11 moon landing on July 20, 1969. It’s also my oldest son’s 15th birthday, but I digress…



We hear a lot about “progress” these days, but it usually involves bailouts, freebies, nanny-state nonsense, deficit spending and perverting the name of “science” to justify unprecedented wealth transfer.



Gene Kratz, retired NASA director of operations, wrote about what fuels actual progress in a 2005 editorial:



All progress involves risk. Risk is essential to fuel the economic engine of our nation. And risk is essential to renew American’s fundamental spirit of discovery so we remain competitive with the rest of the world.

Are we even allowed to say the word “risk” anymore?



Here’s the CBS coverage of the Apollo 11 landing of Neil Armstrong and Buzz Aldrin, while command module pilot Michael Collins orbited, complete with cheeseball graphics of the day, and I still love every second of it:







**Written by Doug Powers



Twitter @ThePowersThatBe

Moon Of Saturn Triggers Giant Snowballs In Planet's F Ring

From Space.com:

Saturn's Moon Triggers Giant Snowballs in Planet's Ring


By Denise Chow

SPACE.com Staff Writer

posted: 20 July 2010

01:00 pm ET

A NASA spacecraft that orbits Saturn has captured new images that show icy particles in the planet's outermost discrete ring that are clumping into giant snowballs, created by the gravitational pull of a nearby moon.



The Cassini spacecraft, which has monitored collisions and disturbances in the gas giant's rings for the last six years, spotted the icy clumping process as the moon Prometheus makes multiple swings by Saturn's F ring – a thin ring orbiting about 87,000 miles (140,000 km) out from the planet. [ Photo of the fan-like structures].



The moon's gravitational pull creates disturbances in the ring material, making wake channels that trigger the formation of objects as large as 12 miles (20 kilometers) in diameter, when smaller masses stick together through their mutual gravitational attraction.



Ads by GoogleFree Space WallpapersGet Cool Space Desktop Wallpapers w Planets, Moons & Stars-Try Them Now

wallpapers.smileycentral.comCoffee Fool BannedGrocery stores won't stock us because we're the truth on fresh!

www.CoffeeFool.comThe natural processes that occur within Saturn's rings can give scientists a glimpse into the mechanisms at work in our early solar system, as planets and moons coalesced out of disks of debris.



"Scientists have never seen objects actually form before," said Carl Murray, a Cassini imaging team member based at Queen Mary, University of London. "We now have direct evidence of that process and the rowdy dance between the moons and bits of space debris."



Murray presented the study July 20 at the Committee on Space Research meeting in Bremen, Germany. The findings were also published July 14 in the online edition of the Astrophysical Journal Letters.



Saturn's F ring



Saturn's relatively thin F ring was discovered by NASA's Pioneer 11 spacecraft in 1979. Prometheus and Pandora, the small moons found on either flank of the F ring, were discovered a year later by NASA's Voyager 1 robotic space probe.



In the years since its discovery, the F ring has undergone constant changes in appearance, and scientists have closely monitored the behavior of the two mischievous moons for answers.



Prometheus, which is larger and closer to Saturn, appears to be the main source of the disturbances in the F ring. At its longest point, the potato-shaped moon is 92 miles (148 km) across.



This moon swerves around Saturn at a speed slightly greater than the speed of the much smaller particles in the planet's F ring. As a result of this discrepancy, and the slightly offset orientation of Prometheus' orbit, the moon laps the F ring particles, stirring them up approximately every 68 days.



"Some of these objects will get ripped apart the next time Prometheus whips around," Murray said. "But some escape. Every time they survive an encounter, they can grow and become more and more stable."



Cassini scientists previously used the spacecraft's ultraviolet imaging spectrograph to detect thickened blobs of material near the F ring, after noticing starlight was partially blocked in that area. These objects may be related to the snowball-like clumps that were discovered by Murray and his colleagues.



Density and life span



The newly-found objects in the F ring also appear dense enough to possess what scientists call "self-gravity." This means that they can attract more particles and accumulate in size as ring particles bounce around in Prometheus' wake, Murray said.



As a result, the giant clumps could be almost as dense as Prometheus itself, but only about one-fourteenth as dense as Earth in comparison.



These snowballs in the F ring also have a higher chance of survival due to their serendipitous location in the Saturn system. The F ring is located at a point that is balanced between the tidal force of Saturn trying to break objects apart, and the self-gravity that pulls objects together.



Still, these giant snowballs have short life spans, likely forming and breaking apart within a few months.



The new study could also help scientists explain the origin of a mysterious object discovered by Cassini scientists in 2004. The object, which has been provisionally named S/2004 S 6 is about 3 to 6 miles (5 to 10 km) in diameter, and occasionally bumps into Saturn's F ring, producing jets of debris in the process.



"The new analysis fills in some blanks in our solar system's history, giving us clues about how it transformed from floating bits of dust to dense bodies," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "The F ring peels back some of the mystery and continues to surprise us."

Scorched Extra-Solar Planet Has Comet-like Tail

From Space.com:

Scorched Alien Planet Has a Comet Tail


By Clara Moskowitz

SPACE.com Senior Writer

posted: 15 July 2010

10:36 am ET



A scorched alien planet is flying so close to its parent star that its atmosphere is being swept off it in a glowing tail like some sort of giant comet, NASA announced Thursday.



The existence of the planet and its strange tail, which was suggested in previous studies, was confirmed recently by NASA's Hubble Space Telescope. These new observations of the gas giant planet, called HD 209458b, suggest strong winds from its nearby star are blowing the atmosphere off the scorched world and shaping it into a comet-like tail.



"Since 2003 scientists have theorized the lost mass is being pushed back into a tail, and they have even calculated what it looks like," said astronomer Jeffrey Linsky of the University of Colorado in Boulder, leader of the study. "We think we have the best observational evidence to support that theory. We have measured gas coming off the planet at specific speeds, some coming toward Earth. The most likely interpretation is that we have measured the velocity of material in a tail."



Ads by GoogleThe 9mm is No DefenseDiscover What Self Defense Masters & The Army Don't Want You To Know

www.CloseCombatTraining.comTake the RealAge TestMillions have already taken this amazing test. What's your RealAge?

RealAge.comThis planet orbits its star from a distance of about 4 million miles (7 million km) – 100 times closer than Jupiter circles the sun – yet the mass of HD 209458b is only slightly less than Jupiter. HD 209458b zips around its star in a short 3.5 days. In contrast, our solar system's fastest planet, Mercury, orbits the sun in 88 days. [Gallery: Strangest Alien Planets]



At such close quarters with its star, HD 209458b's atmosphere is a scorching 2,000 degrees Fahrenheit (1,093 Celsius). Past studies have suggested that it is losing about 10,000 tons of gas every second as material is blown off by its parent star. Eventually, it might be stripped entirely of its gas envelope, leaving behind a liquid core of lava. Even so, it will be a long while before the planet is completely destroyed.



"It will take about a trillion years for the planet to evaporate," Linsky said.



The planet is located 153 light-years from Earth. This world was the first of the few known extrasolar planets that seen to be passing in front of, or transiting, their stars.



The existence of HD 209458b was first suggested in 1999. Subsequent studies found indications of oxygen and carbon in its atmosphere. More recently, it became the first alien world outside our solar system found to have water.



To date, astronomers have found more than 400 extrasolar planets using the transiting method and by studying the wobble induced on stars by planets that orbit them.



Linsky and his team used Hubble's Cosmic Origins Spectrograph to analyze the planet's atmosphere during transiting events. This allows the astronomers to study the structure and chemical makeup of a planet's atmosphere by sampling the starlight that passes through it. The dip in starlight because of the planet's passage, excluding the atmosphere, is very small, only about 1.5 percent. When the atmosphere is added, the dip jumps to 8 percent, indicating a bloated atmosphere.



The data also showed the atmosphere escaping the planet was not all traveling at the same speed.



"We found gas escaping at high velocities, with a large amount of this gas flowing toward us at 22,000 miles per hour," Linsky said. "This large gas flow is likely gas swept up by the stellar wind to form the comet-like tail trailing the planet."

Great Globular Cluster On View

From Space.com:

Night Sky's Great Globular Cluster Visible In Telescopes


By Joe Rao

SPACE.com Skywatching Columnist

posted: 16 July 2010

08:00 am ET

A fascinating deep sky object called the Great Globular Cluster can currently be found in telescopes looking nearly overhead on clear summer nights, and there's good story behind how it and other objects are classified.



How often in looking through books on astronomy have you noticed star clusters and nebulae designated by the letter M, followed by some number? For example: the famous Andromeda Galaxy is known as M31 and the Great Orion Nebula is M42.



The Great Globular Cluster is known as M13 and sits the constellation Hercules. The 'M' stands for the initial of the famed 18th century comet observer, Charles Messier (1730-1817).



Ads by GoogleTelescope Sale: Ends 7/30Free Shipping on Select Telescopes & Up To 20% Off Accessories!

www.Telescope.com/BigSaleMeade Telescopes SaleTop Rated Meade Telescopes Site. Low Prices, 30% Off & Free S/H!

www.Telescopes.comMessier was deeply interested in discovering comets but he was plagued by the same trouble that besets all comet hunters. He kept finding "comets" that were not comets at all but only star clusters and nebulae. His hopes were dashed so often that for his own convenience he kept a list of these deceiving objects, which he published in a catalogue. [Photos: Messier Objects in space]



We will come back to Messier in a moment. First, a few words about the M-object number 13 (or Messier 13 as the Great Globular Cluster is known) in his catalogue.



Celestial Chrysanthemum



To locate Messier 13, look toward the four stars, known as the "Keystone" which supposedly forms the body of Hercules.



A keystone is the stone atop an arch, and has this shape, narrower at one end. It's between the two western stars of the keystone that we can find the Great Globular Cluster of Hercules. It's about a third of the way along a line drawn from the stars Eta to Zeta.



Actually, it was not Messier, but Edmund Halley (of comet fame), who first mentioned it in 1715, having discovered it the previous year: "This is but a little Patch," he wrote, "but it shows itself to the naked Eye, when the Sky is serene and the Moon absent."



Located at a distance of about 25,000 light-years, the Hercules Cluster has been estimated to be a ball of tens of thousands of stars roughly 160 light-years in diameter.



Messier first saw the cluster in June 1764 and described it as a "round and brilliant nebula with a brighter center, which I am sure contains no stars."



Today, if you use good binoculars and look toward that spot in the sky where M13 is you likely will see a similar view: a roundish glow or patch of light. Moving up to a telescope, the view dramatically improves.



With a 4 to 6-inch telescope, the "patch" starts to become resolved into hundreds of tiny pinpoints of light. In larger instruments, Messier 13 is transformed into a spectacular celestial chrysanthemum.



In his Celestial Handbook, the late Robert Burnham described the view of the cluster in a 12-inch or larger telescope as "... an incredibly wonderful sight; the vast swarm of thousands of glittering stars, when seen for the first time or the hundredth, is an absolutely amazing spectacle."



He Couldn't Care Less



Many of the objects listed in Messier's catalogue have turned out to be beautiful star clusters like that in Hercules. Others are great clouds of nebulosity, while still others are galaxies similar to our own.



Yet, there is absolutely no reason to believe that Messier had the slightest interest in these objects. They were all merely a nuisance to him. The 13 comets that Messier discovered and of which he was so proud of are long gone and forgotten now.



But his catalogue, the by-product of his main work, has turned out to be amazingly useful to astronomers. His catalogue numbers have been retained and are the principal reason Messier is still remembered today.



Messier's original list contained 45 such objects and was published in 1774. By 1781, the list had grown to 103.



Historians have since added seven more objects that were seen, but never catalogued by Messier. It has been written by many that Messier had consummate skill in making astronomical observations, even though by contemporary standards the telescopes he utilized were inefficient and crude (that fact is made obvious by his description of the Great Cluster in Hercules).



Nonetheless, he was highly ambitious and always sought recognition of his observing skills and comet discoveries.



One oft-repeated anecdote demonstrates this single-minded and zealous pursuit for finding comets. On the occasion that a rival, Jacques Leibax Montaigne (1716-1785?) discovered a brand new comet, Messier was holding watch at his wife's deathbed.



When a friend later offered condolences for his loss, Messier – thinking only of the comet – answered, "I had discovered twelve, alas, to be robbed of the thirteenth by that Montaigne!" His eyes filled with tears. Then, realizing his friend was commenting about his dead wife, Messier quickly added "Ah! The poor woman..."