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Milky Way Safari

NASA Space Placeby Dauna Coulter and Dr. Tony Phillips

Volunteers study infrared images of our galaxy from the Spitzer Space Telescope, identifying interesting features using the special tools of the Milky Way Project, part of the Citizen Science Alliance Zooniverse web site.
Safari, anyone? Citizen scientists are invited to join a hunt through the galaxy. As a volunteer for Zooniverse's Milky Way Project, you'll track down exotic creatures like mysterious gas bubbles, twisted green knots of dust and gas, and the notorious “red fuzzies.”

“The project began about four months ago,” says astrophysicist Robert Simpson of Oxford University. “Already, more than 18,000 people are scouting the Milky Way for these quarry.”

The volunteers have been scrutinizing infrared images of the Milky Way's inner regions gathered by NASA’s Spitzer Space Telescope. Spitzer's high resolution in infrared helps it pierce the cloaking haze of interstellar gas and dust, revealing strange and beautiful structures invisible to conventional telescopes. The Milky Way Project is helping astronomers catalogue these intriguing features, map our galaxy, and plan future research.

“Participants use drawing tools to flag the objects,” explains Simpson. “So far they've made over a million drawings and classified over 300,000 images.”

Scientists are especially interested in bubble-like objects believed to represent areas of active star formation. “Every bubble signifies hundreds to thousands of young, hot stars. Our volunteers have circled almost 300,000 bubble candidates, and counting,” he says.

Humans are better at this than computers. Computer searches turn up only the objects precisely defined in a program, missing the ones that don't fit a specified mold. A computer would, for example, overlook partial bubbles and those that are skewed into unusual shapes.

“People are more flexible. They tend to pick out patterns computers don't pick up and find things that just look interesting. They're less precise, but very complementary to computer searches, making it less likely we'll miss structures that deserve a closer look. And just the sheer numbers of eyes on the prize mean more comprehensive coverage.”

Along the way the project scientists distill the volunteers' data to eliminate repetitive finds (such as different people spotting the same bubbles) and other distortions.

The project's main site (http://www.milkywayproject.org ) includes links to a blog and a site called Milky Way Talk. Here “hunters” can post comments, chat about images they've found, tag the ones they consider especially intriguing, vote for their favorite images (see the winners at http://talk.milkywayproject.org/collections/CMWS00002u ), and more.

Zooniverse invites public participation in science missions both to garner interest in science and to help scientists achieve their goals. More than 400,000 volunteers are involved in their projects at the moment. If you want to help with the Milky Way Project, visit the site, take the tutorial, and … happy hunting!

You can get a preview some of the bubbles at Spitzer’s own web site, http://www.spitzer.caltech.edu/. Kids will enjoy looking for bubbles in space pictures while playing the Spitzer concentration game at http://spaceplace.nasa.gov/spitzer-concentration/.

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.
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Cosmic Recount

NASA Space Placeby Dr. Tony Phillips

Astronomers have recently found that some galaxies have as many as 2000 small stars for every 1 massive star. They used to think all galaxies had only about 500 small stars for every 1 massive star.
Click image for larger view
News flash: The Census Bureau has found a way to save time and money. Just count the biggest people. For every NBA star like Shaquille O'Neal or Yao Ming, there are about a million ordinary citizens far below the rim. So count the Shaqs, multiply by a million, and the census is done.

Could the Bureau really get away with a scheme like that? Not likely. Yet this is just what astronomers have been doing for decades.

Astronomers are census-takers, too. They often have to estimate the number and type of stars in a distant galaxy. The problem is, when you look into the distant reaches of the cosmos, the only stars you can see are the biggest and brightest. There's no alternative. To figure out the total population, you count the supermassive Shaqs and multiply by some correction factor to estimate the number of little guys.

The correction factor astronomers use comes from a function called the “IMF” — short for “initial mass function.” The initial mass function tells us the relative number of stars of different masses. For example, for every 20-solar-mass giant born in an interstellar cloud, there ought to be about 100 ordinary sun-like stars. This kind of ratio allows astronomers to conduct a census of all stars even when they can see only the behemoths.

Now for the real news flash: The initial mass function astronomers have been using for years might be wrong.

NASA's Galaxy Evolution Explorer, an ultraviolet space telescope dedicated to the study of galaxies, has found proof that small stars are more numerous than previously believed.

“Some of the standard assumptions that we've had — that the brightest stars tell you about the whole population — don't seem to work, at least not in a constant way,” says Gerhardt R. Meurer who led the study as a research scientist at Johns Hopkins University, Baltimore, Md. (Meurer is now at the University of Western Australia.)

Meurer says that the discrepancy could be as high as a factor of four. In other words, the total mass of small stars in some galaxies could be four times greater than astronomers thought. Take that, Shaq!

The study relied on data from Galaxy Evolution Explorer to sense UV radiation from the smaller stars in distant galaxies, and data from telescopes at the Cerro Tololo Inter-American Observatory to sense the “H-alpha” (red light) signature of larger stars. Results apply mainly to galaxies where stars are newly forming, cautions Meurer.

“I think this is one of the more important results to come out of the Galaxy Evolution Explorer mission,” he says. Indeed, astronomers might never count stars the same way again.

Find out about some of the other important discoveries of the Galaxy Evolution Explorer at http://www.galex.caltech.edu/. For an easy-to-understand answer for kids to “How many solar systems are in our galaxy?” go to The Space Place at: http://tiny.cc/I2KMa

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.
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GOES-R, Zombie Fighter

NASA Space Placeby Dr. Tony Phillips

The Galaxy 15 communication satellite was “brainless” for several months in 2010 after being exposed to a geomagnetic storm. The new GOES-R satellite will warn of such dangers.
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On April 5, 2010, something eerie happened to the Galaxy 15 telecommunications satellite: It turned into a zombie.

The day began as usual, with industry-owned Galaxy 15 relaying TV signals to millions of viewers in North America, when suddenly the geosynchronous satellite stopped taking commands from Earth. It was brain dead! Like any good zombie, however, its body continued to function. Within days, Galaxy 15 began to meander among other satellites in geosynchronous orbit, transmitting its own signal on top of the others’. Satellite operators scrambled to deal with the interference, all the while wondering what happened?

In horror movies, zombies are usually produced by viruses.

“In this case, the culprit was probably the sun,” says Bill Denig of the National Geophysical Data Center in Boulder, Colorado. He and colleague Janet Green of NOAA’s Space Weather Prediction Center recently led a study of the Galaxy 15 anomaly, and here are their conclusions:

On April 3rd, a relatively minor solar flare launched a cloud of plasma toward Earth. Galaxy 15 had experienced many such events before, but this time there was a difference.

“Galaxy 15 was just emerging from the shadow of Earth when the cloud arrived and triggered a geomagnetic storm,” explains Denig. Suddenly exposed to sunlight and the ongoing storm, “the spacecraft began to heat up and charge [up].”

Electrons swirling around Galaxy 15 stuck to and penetrated the spacecraft’s surface. As more and more charged particles accumulated, voltages began to rise, and —zap!— an electrostatic discharge occurred. A zombie was born.

“At least, this is what we suspect happened based on data collected by GOES satellites in the vicinity,” he says. “We’ll be able to diagnose events like this much better, however, after GOES-R is launched by NASA in 2015.”

GOES-R is NOAA’s next-generation Geostationary Operational Environmental Satellite. One of the instruments it will carry, a low-energy electron counter, is crucial to “zombie fighting.” Low energy-electrons are the ones most likely to stick to a spacecraft’s surface and cause brain-frying discharges. By monitoring these particles in Earth orbit, GOES-R will provide better post-mortems for future zombie outbreaks. This could help satellite designers figure out how to build spacecraft less susceptible to discharges. Also, GOES-R will be able to issue alerts when dangerous electrons appear. Satellite operators could then take protective action—for example, putting their birds in “safe mode”—to keep the zombie population at bay.

Meanwhile, Galaxy 15 is a zombie no more. In late December 2010, after 9 months of terrorizing nearby spacecraft, the comsat was re-booted, and began responding to commands from Earth again.

All’s well that ends well? True zombie fighters know better than to relax. Says Denig, “we’re looking forward to GOES-R.”

You and the kids in your life can learn about space weather at http://scijinks.gov/space-weather-and-us.

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

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Astronomy From Your Back Yard - 3/2 to 3/8 2011

By Dave Grosvold

The New Moon occurs this week on Friday morning at 2:47 AM CST. Last week we watched the waning crescent moon rise in the eastern sky in the pre-dawn hours, while late this week and early next, we will begin to catch the newly waxing crescent in the western sky starting early Sunday evening. Between now and then, we will be treated to our best dark skies while the Moon is making its monthly pass near the Sun.

Sirius (α Canis Majoris) shines high in the south during the early evenings in early March. Sirius is the brightest star in our sky at magnitude -1.46. Sirius is known as the Dog Star, due to its position of prominence in the constellation Canis Major, and is actually a binary star system. Sirius A, the larger component, is a white main-sequence star, while Sirius B is its white dwarf companion.

Sirius marks the bottom apex of the Winter Triangle asterism, which is now directly south of us in early evening. The other two vertices of the Winter Triangle are Procyon (α Canis Minoris,) in Canis Minor, and Betelgeuse (α Orionis) in Orion. Over the course of the month of March, we will see the Winter Triangle appear to move further west each evening if you look at about the same hour of darkness. Don't forget — we switch to Daylight Saving Time on March 13, so the same hour of darkness occurs about an hour and a half later by the end of the month. So if you look at 7:30 PM tomorrow evening, by the end of the month it will be about 9:00 PM before you will see the sky reach the same darkness level.

Jupiter is sinking down the western sky this week, just a bit lower each day. By Tuesday evening early next week, Jupiter sets by 8:00 PM CST, so early evening is the best time to catch it. Still brighter than Sirius by quite a bit at magnitude -2.1, it is not nearly as bright as it was in late December. In the meantime, Venus at magnitude -4.1 is almost twice as bright, rising in the east-southeast before dawn this time of year. Since they are not both in the sky together, it is difficult to compare the two without instrumentation.

On Sunday evening, look low in the western sky for a very thin waxing crescent Moon almost due west, about 6° to the right and slightly higher than mighty Jupiter (6 degrees would be about 4 finger widths at arm's length.)

Starting early next week, Mercury is a challenging evening object, and is now very low in bright twilight below Jupiter. Starting Monday, very early in the twilight (about 6:15 PM CST,) if you have a very clear sky and you can find an observing location with a low, clear western horizon (like the eastern shore of a lake,) Look close to the horizon with a pair of binoculars directly below the now-thicker waxing crescent Moon and you may find Mercury as a tiny pin-prick of bright light against the glowing sunset background. Mercury will set between 6:30 PM and 6:45 PM CST, so you don't have a lot of time to look. The visibility of objects in bright twilight is greatly exaggerated in the accompanying image, but you get the idea.

Saturn rises in Virgo around 8 PM CST, but it's best to wait to observe it with a telescope until it gains high altitude, clearing the bad seeing due to the thicker atmosphere at the horizon. Saturn is highest in the south around 2 AM CST. Spica (α Virginis,) slightly fainter, shines about 9° below Saturn all evening and into the early morning hours. Saturn's rings are tilted at about 9.7° with respect to Earth right now, so they should easily be visible in small telescopes. Look for Saturn's moons while you have it centered in your eyepiece.

The International Space Station (ISS) will make several bright passes over our area early next week. Look for the ISS to pass low in the NE (from the NNE to the NE) at an altitude of 10° at 7:05 PM CST on Sunday. This pass will be at magnitude -1.0, which is about the same as Regulus in Leo. On Monday evening, the ISS passes over our northern sky at an altitude of 25° at 7:31 PM CST. This time, it will reach magnitude -2.3, or slightly brighter that Venus. Then Tuesday evening, the ISS passes high over our northwestern sky at 7:56 PM, reaching an altitude of 50° and a magnitude of -2.8, which will be brighter than anything else in the sky at that hour.
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General NewsAn Astro Safari has been organized to Namibia starting on the 30th April 2011, finishing 9th May 2011.
The trip is astronomy-biased with side trips to Namibia's wild life reserves.
The astronomy portion will be led by Mr. Andy Bender, a German astronomer (http://www.astropic.de,)
while the safaris are to be run by experienced safari guides.

The flyer, and indeed the entire trip, will be in the English language.

For further information, please click on the following link to send an e-mail:
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Astronomy From Your Back Yard - 2/16 to 2/22 2011

By Dave Grosvold

Aurora over Fairbanks, Alaska, October 26, 2007
Photo by Mila Zinkova
Unfortunately, the chances are much lower for seeing the Aurora Borealis or "northern lights" than were reported earlier. The recent coronal mass ejection (CME, or solar flare) from Sunspot 1158 will hitting our planet's magnetic field for the next 24 - 48 hours. The chances of seeing an aurora at high latitudes (50°N,) are now down to 45%, with much slimmer chances (less than 5%,) that they will reach as low as 35°N, the latitude of NW Arkansas. There will be more chances over the next few years though as the number of CMEs is now on the increase.

NASA Photo
However, for another unusual treat, sky observers stand a good chance of viewing the Zodiacal Light from Fort Smith and NW Arkansas during the last half of this month. Starting on Saturday evening, find a dark sky location with a clear western horizon, wait for your eyes to dark-adapt, and be prepared to start looking west along the horizon about an hour and a half after sunset. If the zodiacal light is visible, you will see a vague, huge pyramid of softly glowing light sloping toward the south along the line of the ecliptic. Don't give up if you don't see it the first time you go out. This phenomenon will occur in the evenings from Saturday over the next 10 days or so.

On Thursday evening, look to the left or lower left of the Moon after dark for Regulus. Farther left of them is Gamma Leonis, not much fainter than Regulus. Look farther to the Moon's lower right for orange Alphard.

The Full Moon occurs this week at 2:36 AM CST Friday morning. On Friday evening, look for Regulus about a fist-width above the Moon. Regulus marks the bottom-right end of the Sickle (actually the bottom of the Sickle's handle.) The Sickle is an asterism in the constellation Leo. Also on Friday evening, at 6:20 PM CST, look straight to the north toward Polaris to catch Iridium 13 as it flares to an intensely bright magnitude -8.0.

At dusk this week, Jupiter shines brightly in the west-southwest and then sets in the west by around 8:00 PM CST. The best time to view it is in late twilight while it's still high. The South Equatorial Belt continues to re-form. Uranus has drifted away from Jupiter to the west and they are now separated by about 6°. They will continue to drift apart as the month progresses.

  At around 10:30 PM CST this week, Saturn rises in Virgo. By the end of the month, it will rise about an hour earlier. Last month Saturn was less than 8° from Spica, but now Saturn is moving away since it's reached a place in its orbit where it displays apparent retrograde motion. By 3:30 AM CST, Saturn culminates (passes its highest point in the night sky.) Saturn's rings are 10° from edge on, their maximum for this year.

On Monday morning, Feb 21, Saturn and Spica form an equilateral triangle with the Moon in the pre-dawn darkness of the southwester sky. Monday evening at 7:34 PM CST gives us another chance to catch an Iridium Flare, this time Iridium 39, in the south-southeast, also at a brilliant magnitude -8.0.

In the east all this week, an hour or so before dawn while the sky is still fully dark, Venus rises and climbs until it is lost in the glow of sunrise. Venus has lost a bit of its luster, dropping from magnitude -4.3 to -4.1 while its phase increases to more than 70% lit, but still remains the brightest object in the morning sky — our "Morning Star". How can this be? Venus is drawing further away from Earth as its phase increases, so the apparent brightness is actually lower.

Unfortunately, Mercury, Mars, and Neptune are hidden behind the glare of the Sun this week.

The International Space Station (ISS) will also make several passes overhead this week that will be brighter or equal to magnitude -2.5. Saturday evening, at 6:58 PM CST, the ISS at magnitude -2.8, will pass low in the SE at an altitude of 34°. On Sunday at 7:14 PM CST, the ISS will pass mid-way up the NW sky at altitude or 49° also with a brightness of magnitude -2.8. Then on Tuesday evening, it will reach a magnitude of -2.5, again passing mid-way up the sky (42°)in the NW at 6:30 PM CST.
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Thank Goodness the Sun is Single

NASA Space PlaceBy Trudy E. Bell

Planetary collisions such as shown in this artist’s rendering could be quite common in binary star systems where the stars are very close.
Click image for larger view
It’s a good thing the Sun is single. According to new research, Sun-like stars in close double-star systems “can be okay for a few billion years — but then they go bad,” says Jeremy Drake of the Harvard-Smithsonian Astrophysical Observatory in Cambridge, Mass.

How bad? According to data from NASA’s Spitzer Space Telescope, close binary stars can destroy their planets along with any life. Drake and four colleagues reported the results in the September 10, 2010, issue of The Astrophysical Journal Letters.

Our Sun, about 864,000 miles across, rotates on its axis once in 24.5 days. “Three billion years ago, roughly when bacteria evolved on Earth, the Sun rotated in only 5 days,” explains Drake. Its rotation rate has been gradually slowing because the solar wind gets tangled up in the solar magnetic field, and acts as a brake.

But some sun-like stars occur in close pairs only a few million miles apart. That’s only about five times the diameter of each star — so close the stars are gravitationally distorted. They are actually elongated toward each other. They also interact tidally, keeping just one face toward the other, as the Moon does toward Earth.

Such a close binary is “a built-in time bomb,” Drake declares. The continuous loss of mass from the two stars via solar wind carries away some of the double-star system’s angular momentum, causing the two stars to spiral inward toward each other, orbiting faster and faster as the distance shrinks. When each star’s rotation period on its axis is the same as its orbital period around the other, the pair effectively rotates as a single body in just 3 or 4 days.

Then, watch out! Such fast spinning intensifies the magnetic dynamo inside each star. The stars “generate bigger, stronger ‘star spots’ 5 to 10 percent the size of the star — so big they can be detected from Earth,” Drake says. “The stars also interact magnetically very violently, shooting out monster flares.”

Worst of all, the decreasing distance between the two stars “changes the gravitational resonances of the planetary system,” Drake continued, destabilizing the orbits of any planets circling the pair. Planets may so strongly perturbed they are sent into collision paths. As they repeatedly slam into each other, they shatter into red-hot asteroid-sized bodies, killing any life. In as short as a century, the repeated collisions pulverize the planets into a ring of warm dust.

The infrared glow from this pulverized debris is what Spitzer has seen in some self-destructing star systems. Drake and his colleagues now want to examine a much bigger sample of binaries to see just how bad double star systems really are.

They’re already sure of one thing: “We’re glad the Sun is single!”

Read more about these findings at the NASA Spitzer site at http://www.spitzer.caltech.edu/news/1182-ssc2010-07-Pulverized-Planet-Dust-May-Lie-Around-Double-Stars . For kids, the Spitzer Concentration game shows a big collection of memorable (if you’re good at the game) images from the Spitzer Space Telescope. Visit http://spaceplace.nasa.gov/en/kids/spitzer/concentration/.

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.
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Planets in Strange Places

NASA Space PlaceBy Trudy E. Bell

Artist’s rendering compares size of a hypothetical hypergiant star and its surrounding dusty disk to that of our solar system.
Click image for larger view
Red star, blue star, big star, small star — planets may form around virtually any type or size of star throughout the universe, not just around mid-sized middle-aged yellow stars like the Sun. That’s the surprising implication of two discoveries in 2006 from the 0.85-meter-diameter Spitzer Space Telescope, which is exploring the universe from orbit at infrared (heat) wavelengths blocked by the Earth’s atmosphere.

At one extreme are two blazing, blue “hypergiant” stars 180,000 light-years away in the Large Magellanic Cloud, one of the two companion galaxies to our Milky Way. The stars, called R 66 and R 126, are respectively 30 and 70 times the mass of the Sun, “about as massive as stars can get,” said Joel Kastner, professor of imaging science at the Rochester Institute of Technology in New York. R 126 is so luminous that if it were placed 10 parsecs (32.6 light-years) away — a distance at which the Sun would be one of the dimmest stars visible in the sky — the hypergiant would be as bright as the full moon, “definitely a daytime object,” Kastner remarked.

Such hot stars have fierce solar winds, so Kastner and his team are mystified why any dust in the neighborhood hasn’t long since been blown away. But there it is: an unmistakable spectral signature that both hypergiants are surrounded by mammoth disks of what might be planet-forming dust and even sand.

At the other extreme is a tiny brown dwarf star called Cha 110913-773444, relatively nearby (500 light-years) in the Milky Way. One of the smallest brown dwarfs known, it has less than 1 percent the mass of the Sun. It’s not even massive enough to kindle thermonuclear reactions for fusing hydrogen into helium. Yet this miniature “failed star,” as brown dwarfs are often called, is also surrounded by a flat disk of dust that may eventually clump into planets. (This brown dwarf discovery was made by a group led by Kevin Luhman of Pennsylvania State University.)

Although actual planets have not been detected (in part because of the stars’ great distances), the spectra of the hypergiants show that their dust is composed of forsterite, olivine, aromatic hydrocarbons, and other geological substances found on Earth.

These newfound disks represent “extremes of the environments in which planets might form,” Kastner said. “Not what you’d expect if you think our solar system is the rule.” Hypergiants and dwarfs? The Milky Way could be crowded with worlds circling every kind of star imaginable — very strange, indeed.

Keep up with the latest findings from the Spitzer at www.spitzer.caltech.edu. Kids and their grownup friends can enjoy beautiful images from Spitzer while playing Spitzer Concentration at The Space Place (spaceplace.nasa.gov/en/kids/spitzer/concentration).

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.
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Astronomers Stumble onto Huge Space Molecules

NASA Space PlaceBy Trudy E. Bell and Tony Phillips

Superimposed on a Spitzer infrared photo of the Small Magellanic Cloud is an artist's illustration depicting a magnified view of a planetary nebula and an even further magnified view of buckyballs, which consist of 60 carbon atoms arranged like soccer balls.
Click image for larger view
Deep in interstellar space, in a the swirling gaseous envelope of a planetary nebula, hosts of carbon atoms have joined together to form large three-dimensional molecules of a special type previously seen only on Earth. Astronomers discovered them almost accidentally using NASA's Spitzer Space Telescope.

“They are the largest molecules known in space,” declared Jan Cami of the University of Western Ontario, lead author of a paper with three colleagues published in Science online on July 22, 2010, and in print on September 3.

Not only are the molecules big: they are of a special class of carbon molecules known as “fullerenes” because their structure resembles the geodesic domes popularized by architect Buckminster Fuller. Spitzer found evidence of two types of fullerenes. The smaller type, nicknamed the “buckyball,” is chemical formula C60, made of 60 carbon atoms joined in a series of hexagons and pentagons to form a spherical closed cage exactly like a black-and-white soccer ball. Spitzer also found a larger fullerene, chemical formula C70, consisting of 70 carbon atoms in an elongated closed cage more resembling an oval rugby ball.

Neither type of fullerene is rigid; instead, their carbon atoms vibrate in and out, rather like the surface of a large soap bubble changes shape as it floats through the air. “Those vibrations correspond to wavelengths of infrared light emitted or absorbed—and that infrared emission is what Spitzer recorded,” Cami explained.

Although fullerenes have been sought in space for the last 25 years, ever since they were first identified in the laboratory, the astronomers practically stumbled into the discovery. Co-author Jeronimo Bernard-Salas of Cornell University, an expert in gas and dust in planetary nebulae, was doing routine research with Spitzer's infrared observations of planetary nebulae with its spectroscopy instrument. When he studied the spectrum (infrared signature) of a dim planetary nebula called TC 1 in the southern — hemisphere constellation of Ara, he noticed several clear peaks he had not seen before in the spectra of other planetary nebulae.

“When he came to me,” recounted Cami, an astrophysicist who specializes in molecular chemistry, “I immediately and intuitively knew it I was looking at buckyballs in space. I've never been that excited!” The authors confirmed his hunch by carefully comparing the Tc 1 spectrum to laboratory experiments described in the literature.

“This discovery shows that it is possible — even easy — for complex carbonaceous molecules to form spontaneously in space,” Cami said. “Now that we know fullerenes are out there, we can figure out their roles in the physics and chemistry of deep space. Who knows what other complex chemical compounds exist—maybe even some relevant to the formation of life in the universe!”

Stay tuned!

Learn more about this discovery at http://www.spitzer.caltech.edu. For kids, there are lots of beautiful Spitzer images to match up in the Spitzer Concentration game at http://spaceplace.nasa.gov/en/kids/spitzer/concentration.

This article was provided by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.
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Astronomy From Your Back Yard - 1/5 to 1/11 2011

By Dave Grosvold

Happy New Year! Things are “looking up” in backyard astronomy — at least for the remainder of this week. With the skies relatively clear until the weekend, and the waxing crescent Moon, the resulting sky glow is not bright enough to present much of a problem for evening sky watchers.

One of the most spectacular sights to be had for amateur astronomers on these cold clear winter evenings is the central region of the constellation of Orion. This region is home to large bright nebulae and open clusters easily visible in a small telescope or binoculars. I mentioned M42, the Great Orion Nebula which is the brightest deep sky object in this region last year at this time.

Two objects in this area besides M42 are special treats. The first, NGC 1977, is known as the Running Man Nebula. NGC 1977 is a beautiful blue emission nebula with a dark reflection nebula inside it. Because of the reflected glow from brighter and larger M42, the darker parts of NGC 1977 reflects the colorful hues of M42 and imbue it with a mysterious, ghostly quality. Some have come to refer to NGC 1977 as the Ghost Nebula for this reason.

The second object, NGC 1981, is a large open cluster just above NGC 1977. NGC 1981 is a beautiful sprinkling of 10 or 11 bright stars in the Orion-Cygnus Arm of the Milky Way Galaxy, peppered with a background of the much more distant stars of other regions of the Milky Way. All of the stars in the cluster and the two nebula mentioned above are relatively close neighbors of the Solar System, at a mean distance of only about 700 light years from Earth. This makes it one of the nearest star forming regions we have available for study.

Two other deep sky objects in this region surround the star known as Alnitak, or Zeta Orionis (ζ Ori.) This triple star system, the easternmost star in the Belt of Orion, is surrounded by two well-known faint emission nebula, B33, the Horsehead Nebula, and NGC 2024, the Flame Nebula. These are normally not visible in small telescopes or binoculars, but they are a popular target for astro-imagers.

By 7:30 PM CST Wednesday evening, the Moon has set and the Winter Triangle is well up in the east-southeast, consisting of Betelgeuse in Orion's leftmost corner, bright Sirius in Canis Major below and to the right, and Procyon in Canis Minor to the left of these two. The Winter Triangle is brighter and more colorful than it's well-known summer counterpart. An even larger asterism, the Winter Hexagon, includes Procyon and Sirius, along with four other bright, colorful stars in the eastern evening sky: Rigel in Orion; Aldebaran in Taurus; Capella in Auriga; and Pollux in Gemini.

The brightest "star" in the evening sky this week is NOT a star, but a planet! As the current Evening Star, Jupiter still shines at magnitude -2.3 in Pisces, high in the south above Fomalhaut in Piscis Austrinus. Jupiter is receding from us as Earth begins to round the far side of the Sun from Jupiter, so it appears only 38 arcseconds wide. However, Jupiter is still wide enough to see the South Equatorial Belt re-forming and the transits of the Great Red Spot in a small-to-medium telescope. Uranus is now very close to Jupiter, just 0.6° to the west of the larger planet. Both planets should be close enough so they are both visible in the same field of view in a small telescope when using a medium power eyepiece. A third planet, Neptune, is also still visible in the early evening southwestern sky west of Fomalhaut, on the border between Aquarius and Capricornus. This one is much harder to spot and requires a small telescope or binoculars.

Bright Saturn rises about 30 minutes past midnight this week. By 3:30 AM CST, Saturn is in a perfect position for viewing, high in the southeastern sky in Virgo. That puts it above the thick lower atmosphere long before the sky glow begins in the east as the rising Sun approaches the horizon. The rings are tilted now at about 10°, widening as spring approaches. The rings haven't been this wide since 2007.

Later in the morning this week, very near dawn, Venus shines in the southeastern sky. Though very bright at magnitude -4.3, viewing Venus, in a telescope reveals itself to be only half-lit. Venus is very nearly at it's greatest elongation from the Sun. Venus will begin to grow gibbous in the coming months, while shrinking in diameter as it begins to swing around the far side of the Sun in its faster orbit.

Mercury, too, will be relatively bright at magnitude 0, low in the southeastern sky just before dawn. Notice fainter Antares in Scorpius and the rest of the starry background of the Milky Way, rising in the east before dawn as the winter season marches on.

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Become a card-carrying member of AOAS. Paying dues gives you several advantages over other registered users, including a subscription to the club newsletter, an AOAS.ORG e-mail address, use of club materials, including books and telescopes, and access to the Coleman Observatory facilities. On top of all that, you also qualify for a 20% discount on all books at any Books-A-Million location.

To get your membership application, click here.