NASA Spacecraft Snaps New Photo of Potential 'Comet of the Century'

A NASA spacecraft scanning for the most powerful explosions in the universe has captured a photo of Comet ISON, an icy wanderer that could potentially dazzle stargazers when it swings close to the sun later this year.

NASA's Swift satellite, which is typically used to track intense gamma-ray bursts from distant stars, photographed Comet ISON on Jan. 30, with the space agency unveiling the photo today (March 29). By tracking the comet over the last two months, Swift has allowed astronomers to learn new details about how large the comet is and how fast it is spewing out gas and dust.

"Comet ISON has the potential to be among the brightest comets of the last 50 years, which gives us a rare opportunity to observe its changes in great detail and over an extended period," said Lead Investigator Dennis Bodewits, an astronomer with University of Maryland at College Park (UMCP) who helped obtain the new image.

Some astronomers have predicted that ISON could be the "Comet of the Century" when it makes its closest approach to the sun in late November. But a recent analysis found that the comet is not brightening as expected, and may have a ways to go to meet such expectations.

Comet ISON was first discovered in September 2012 by Russian astronomers Vitali Nevski and Artyom Novichonok using the International Scientific Optical Network (ISON) located near Kislovodsk. The comet's official designation is Comet C/2012 S1 (ISON). [See more photos of Comet ISON]

Swift's Comet ISON view

Bodewits and his university colleagues teamed up with the Lowell Observatory in Flagstaff, Ariz., to capture new views of Comet ISON using the Swift spacecraft. The satellite's Jan. 30 photo shows the comet as a bright, fuzzy white ball. At the time, Comet ISON was about 375 million miles (670 million kilometers) from Earth and 460 million miles (740 million km) from the sun.

"Using images acquired over the last two months from Swift's Ultraviolet/Optical Telescope (UVOT), the team has made initial estimates of the comet's water and dust production and used them to infer the size of its icy nucleus," NASA officials wrote in a statement.

Swift's observations revealed that Comet ISON is currently shedding about 112,000 pounds (51,000 kilograms) of dust and about 130 pounds (60 kg) of water every minute, an odd mismatch for such an anticipated comet.

All comets are made of dust and frozen gases that mix together to form a sort of "dirty snowball" in space, NASA officials explained. Water ice in comets typically stays frozen until the comet approaches within three times the Earth's distance to the sun, at which time the water ice heats up and changes directly into gas (a process called sublimation), creating jets of material that can brighten the comet.

"The mismatch we detect between the amount of dust and water produced tells us that ISON's water sublimation is not yet powering its jets because the comet is still too far from the sun," Bodewits said. "Other more volatile materials, such as carbon dioxide or carbon monoxide ice, evaporate at greater distances and are now fueling ISON's activity."

Currently, Comet ISON is about 5,000 times fainter than the dimmest object the human eye can see.

NASA's Comet ISON campaign

NASA's Swift spacecraft is one of several satellites and probes to observe Comet ISON as it passes through the inner solar system. The space agency has formed the Comet ISON Observing Campaign (CIOC) to make the most of the comet's visit.

On Oct. 1, the comet will pass within 6.7 million miles (10.8 million km) of Mars, and may be spotted by orbiters around the Red Planet. [Comet ISON's Path Through Solar System (Video)]

"During this close encounter, Comet ISON may be observable to NASA and ESA spacecraft now working at Mars," said Michael Kelley, a UMCP astronomer and also a Swift and CIOC team member. "Personally, I'm hoping we'll see a dramatic postcard image taken by NASA's latest Mars explorer, the Curiosity rover."

On Nov. 28 — 58 days after swing close by Mars — Comet ISON will make its closest approach to the sun, flying within 730,000 miles (1.2 million km) of the star's surface during the encounter. Several sun-watching observatories will be tracking the comet at that time, and ISON may even become visible in the daytime sky to observers who block the sun's light with their hand, NASA officials said.

The comet will make its closest approach to Earth on Dec. 26, coming with 39.9 million miles (64.2 million km) of the planet as a late Christmas present.

But whether Comet ISON will live up to its celestial hype or fizzle out in a whimper still remains to be seen, astronomers warned. The comet must still survive the approach into the inner solar system, as well as its close encounter with the sun.

"It looks promising, but that's all we can say for sure now," Matthew Knight, an astronomer at Lowell Observatory said. "Past comets have failed to live up to expectations once they reached the inner solar system, and only observations over the next few months will improve our knowledge of how ISON will perform."

Editor's note: If you snap an amazing photo of Comet ISON or any other celestial object, and you'd like to share for a possible story or image gallery, please send images and comments, including location information, to Managing Editor Tariq Malik at spacephotos@space.com.

Email Tariq Malik at tmalik@space.com or follow him @tariqjmalik and Google+. Follow us @Spacedotcom, Facebook and Google+. Original article on SPACE.com.

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NASA's Dawn Spacecraft Discovers Mountain on Asteroid Vesta 'Higher Than Mount Everest' (ContributorNetwork)

NASA's Dawn space craft has taken an image of a mountain on the asteroid Vesta that is higher than Mount Everest, according to the U.K. Daily Mail. It is the latest in spectacular pictures taken by the probe now orbiting the asteroid.

* The mountain, as yet unnamed, is 13 miles high and is surrounded by features that scientists believe were caused by landslides. By contrast Mount Everest is about 5 1/2 miles high.

* Dawn has also imaged a mysterious dark spot on Vesta's equator, about 60 miles wide.

* Dawn was launched from Earth on Sept 27, 2007. It used Mars for a gravity assist in February 2009. It arrived at Vesta in July. It will depart from orbit around Vesta in July 2012 and arrive at Ceres, the largest asteroid in the solar system, in February 2015.

* Dawn used an ion propulsion system to fly to Vesta, a voyage that took nearly four years.

* Dawn's instruments include a framing camera, a visible and infrared spectrometer, and a gamma ray and neutron spectrometer.

* Dawn's primary objective is to gain a better understanding of the origins of the solar system by studying Vesta and then Ceres at close range.

* Dawn is orbiting Vesta at a height of 420 miles, circling the asteroid every 12.3 hours.

* Dawn has completed a series of orbits designed to image Vesta's features straight down. It will now image those same features at an angle. This will aid in the creation of topographical maps of the asteroid as whereas stereo images of individual features. The images are being taken in both visible and infrared light.

* Vesta was discovered by German astronomer and physician Wilhelm Olbers on March 29, 1807.

* Vesta is named after the ancient Roman goddess of the hearth.

* Vesta's orbit around the sun takes 3.63 years.

* Vesta is an irregularly shaped body with an approximant diameter of 530 kilometers.

* Vesta rotates every 5.342 hours.

* Vesta's surface is silicate rock with a nickel-iron core. It is thought not to have accreted a lot of water or may have lost most of its water in the distant past.

* Scientists believe that Vesta suffered a major impact from another body almost its side, creating a crater that reaches deep within its mantle, exposing the material within. This gives Dawn an opportunity to examine that material remotely and perhaps gain some insights into the mantles of other celestial bodies, such as Earth or Mars.

Mark R. Whittington is the author of Children of Apollo and The Last Moonwalker. He has written on space subjects for a variety of periodicals, including The Houston Chronicle, The Washington Post, USA Today, the L.A. Times and The Weekly Standard.

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NASA Launches Twin Spacecraft to Probe Inside the Moon (SPACE.com)

Two identical space probes are on their way to the moon, after launching today (Sept. 10) on NASA's newest lunar science mission aimed at unlocking mysteries of the moon that are hidden beneath its surface.

The two Grail spacecraft blasted off this morning on an unmanned Delta 2 rocket at 9:08 a.m. EDT (1308 GMT) from the Cape Canaveral Air Force Station in Florida, after windy weather and a technical glitch delayed the mission's launch by two days and threatened to again. A first try earlier today at 8:29 a.m. EDT (1229 GMT) was called off due to high-altitude winds, but weather conditions improved, and the agency was able to take advantage of the day's second launch opportunity.

The $496 million Grail mission (short for Gravity Recovery And Interior Laboratory) will closely study the interior of the moon, from crust to core, and will map the moon's gravitational field in unprecedented detail. The three-month mission is expected to help scientists better understand the composition of Earth's natural satellite and its evolutionary history since it was formed 4.6 billion years ago. [Photos of NASA's Grail Moon Mission]

"We've used gravity science before, however these have been very primitive attempts compared to what Grail will be able to accomplish," Robert Fogel, Grail program scientist at NASA Headquarters in Washington, D.C., said in a news briefing on Wednesday (Sept. 7).

Understanding how the origin of the moonand how it evolved will shed light on how other rocky planets in the inner solar system formed, said Maria Zuber, Grail principal investigator at MIT.

"We have orbital reconnaissance of the surface, we have lunar samples which we can analyze in Earth labs," Zuber said. "The piece of the puzzle that has been missing in trying to reconstruct lunar evolution is understanding of the lunar interior." [Related: 20 Most Marvelous Moon Missions]

The two spacecraft, called Grail-A and Grail-B, are flying on an energy-efficient path to the moon, and are expected to arrive at their lunar target around New Year's Day (Jan. 1).

The twin probes will then enter into tandem orbits around the moon, separated from each other by a distance of about 75 to 225 miles (121 to 362 kilometers). The spacecraft will circle the moon about 34 miles (55 km) above the surface.

As the Grail spacecraft chase each other around the moon, regional differences in the lunar gravitational field will cause the probes to speed up or slow down, changing the distance between them, explained Sami Asmar, Grail deputy project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

Microwave signals bounced back and forth between Grail-A and Grail-B will measure this distance, which will help researchers construct accurate maps of the moon's gravity. The instruments onboard the Grail probes are so precise they will be able to calculate the distance between them to within less than the width of a human red blood cell, Asmar said. [Video: Grail's Mission to Map Moon Gravity]

Understanding how the moon formed and evolved will help scientists piece together clues of how other large objects in the inner solar system came to be.

"The moon is a fantastic body … in terms of learning about early planets," Zuber said. "It's nearby, it's accessible, and it preserves the record of what early planets are like. Other planets in the inner part of the solar system have gone through the same processes that the moon has gone through."

The Grail mission is also expected to raise public awareness about the moon, and special cameras aboard the probes will be used to encourage middle school students to participate in lunar science and follow along with the Grail expedition.

The so-called MoonKam project, which will capture pictures of the lunar surface for students on Earth, is being led by former NASA astronaut Sally Ride and her educational company Sally Ride Science.

As part of their public outreach efforts, NASA also invited 150 Twitter fans to attend the launch and share their experiences with the public through social media.

You can follow SPACE.com staff writer Denise Chow on Twitter @denisechow. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.

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NASA prepping next Mars spacecraft for fall launch (AP)

PASADENA, Calif. – NASA's next roving spacecraft to the surface of Mars has arrived in Florida after a cross-country flight to undergo final testing.

A C-17 cargo jet carrying the rover nicknamed Curiosity took off from March Air Force Base in California and arrived Wednesday night in Florida.

Engineers will spend the next several months prepping the rover for its November launch.

The $2.5 billion mission was supposed to fly in 2009, but problems during development pushed costs up and delayed launch.

Curiosity is scheduled to land in August 2012 and will study whether the Martian environment was ever favorable for microbial life.

NASA's Jet Propulsion Laboratory manages the program, formally known as the Mars Science Laboratory.

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NASA Spacecraft Reveals Mercury's Surprising 'Personality' (SPACE.com)

A NASA spacecraft circling Mercury is returning spectacular photos of the planet — and delivering some tantalizing surprises about the tiny, scorched world.

On March 17, NASA's Messenger probe became the first spacecraft ever to orbit Mercury. Since then, Messenger has already snapped more than 20,000 pictures and made observations that could help unlock long-standing mysteries of the solar system's innermost planet, researchers announced at a press conference today (June 16).

"We had many Latest Messenger Photos of Mercury]

Mercury has 'personality'

Messenger is photographing every inch of Mercury's surface from orbit, and some of its early pictures have revealed huge expanses of volcanic deposits near the planet's north pole. These features were detected by Messenger and NASA's Mariner 10 probe on previous Mercury flybys, but the new observations map them out in greater detail. [Infographic: The Messenger Mission]

"Now we're seeing their full extent for the first time," said Messenger scientist Brett Denevi of Johns Hopkins University's Applied Physics Laboratory (APL). And that extent is impressive; the northern volcanic plains cover 1.54 million square miles (4 million square kilometers) — nearly half the size of the continental United States.

These new observations help confirm that volcanism has substantially shaped Mercury's crust and surface for much of its history, researchers said.

Messenger has been scrutinizing Mercury with more than just its camera gear. The probe's X-ray spectrometer, for example, has already discovered that the planet's surface is made of different stuff than the moon, which is dominated by feldspar-rich rock.

The spectrometer has also detected surprisingly high levels of sulfur at the planet's surface, which could help scientists understand the nature of Mercury's origin and volcanism, researchers said.

So far, the spacecraft's observations are putting the lie to the notion that Mercury is similar to the moon. In fact, the early returns indicate that it's also very different than the other terrestrial planets, in ways that are only just beginning to come clear.

"Mercury really is a world in and of its own," said Messenger project scientist Ralph McNutt of APL. "Just like the Earth, it's got its own personality."

Water ice on Mercury?

Messenger is using another one of its seven instruments, a laser altimeter, to map out Mercury's topography. The spacecraft has already taken more than 2 million laser-ranging readings, revealing the planet's geological features in great detail.

"We're seeing the broad shape of the planet for the first time," Solomon said.

One of the many questions Messenger hopes to answer is whether or not Mercury harbors water ice on its surface. That might not seem very likely, since average surface temperatures on the planet can top 842 degrees Fahrenheit (450 degrees Celsius). However, Earth-based radar observations from 20 years ago suggest large amounts of ice may lurk in permanently shadowed craters at its poles.

And the early results from Messenger, which is mapping those craters with its altimeter, support this idea. Thus far, the probe's data indicate that some polar craters may be so deep that their floors are in permanent shadow. Whether they actually contain ice will have to be confirmed by different instruments, researchers said.

"Stay tuned," Solomon said. "The very first scientific test of that hypothesis using Messenger data from orbit has passed with flying colors."

Magnetic fields and more

Messenger has also been investigating the nature of Mercury's global magnetic field, which is of interest partly because Mercury is the only rocky planet in the solar system to possess one, other than Earth.

Mercury's magnetic field was thought to be more or less a miniature version of Earth's, researchers said. But Messenger's readings are showing that's not the case.

For starters, Mercury's magnetic field is asymmetrical, with its magnetic equator lying significantly north of the planet's geographic equator. This surprising geometry suggests that Mercury's south polar region is much more exposed than the north to bombardment by charged particles from the sun.

Scientists don't fully understand the import of many of Messenger's early findings. The probe is just 25 percent of the way through its planned one-year science mission around Mercury, after all.

"There's a lot more to come," McNutt said. "All I can say is to keep following us — the best is yet to be."

A long trip to Mercury

The $446 million Messenger mission — whose name is short for MErcury Surface, Space ENvironment, GEochemistry, and Ranging — launched in August 2004.  It is designed to map Mercury fully for the first time and help answer several key questions about the planet. [The Greatest Mysteries of Mercury]

Mission scientists hope to learn, for example, why Mercury is so much denser than the other rocky planets. And they want to gain insights into how the planet's core is structured, the nature of its global magnetic field and other aspects of Mercury's composition and history. 

Scientists hope all of this information will lead to an increased understanding of how our solar system — and solar systems in general — formed and evolved, researchers have said.

The spacecraft is now in an extremely oblong, or elliptical, orbit that brings it within 124 miles (200 kilometers) of Mercury at the closest point and retreats to more than 9,300 miles (15,000 km) away at the farthest point. Its orbital science mission is designed to last for 12 months.

While Messenger is the first mission ever to orbit Mercury, it is not the first spacecraft to visit the planet. NASA's Mariner 10 spacecraft flew by the planet three times in the mid-1970s. Messenger itself also made three flybys of the planet on its long, circuitous space journey, snapping photos all the while.

You can follow SPACE.com senior writer Mike Wall on Twitter: @michaeldwall. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.

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Russian spacecraft blasts off for space station (AP)

BAIKONUR, Kazakhstan – A Russian Soyuz craft lit up the starry skies of the southern Kazakh steppe early Wednesday as it blasted off to carry a three-man crew for a mission to the International Space Station that will take in the U.S. shuttle's farewell voyage.

Russian cosmonaut Sergei Volkov, NASA's Michael Fossum, and Satoshi Furukawa of Japan's JAXA space agency will spend almost two days squeezed into the cramped Soyuz capsule before docking with the space station, where they will remain until mid-November.

By being present on the space station as the shuttle performs its final voyage, Fossum and fellow NASA astronaut Ron Garan will play leading roles in the closing act of the program.

"They're going to be very proud to be part of the last shuttle dock mission. It's obviously going to be a sad time for all of us to see the end of the program," said NASA colleague Jeff Williams, who accompanied Fossum's family during their stay in Baikonur.

Overnight, however, all attention was on the spectacle of the simple and powerful Soyuz performing its duties.

At 2:15 a.m Wednesday (2015 GMT Tuesday), the ferocious roar of rockets echoed around the desolate expanses of the Russian-leased Baikonur space launch site as the Soyuz capsule was propelled into heavens, delighting the astronauts' families, friends and colleagues.

Furukawa gave a thumbs-up sign as the rocket charged into low orbit at speeds approaching 14,000 miles per hour (23,000 kilometers per hour), and a soft toy began to float, indicating zero gravity.

"We feel just great," Volkov said in answer to a question from mission control outside Moscow.

Within seconds, the phosphorous white intensity of the heavens above the Central Asian plains faded and the Soyuz blended into the stars.

Among the spectators at the viewing platform was JAXA astronaut Soichi Noguchi, who last year also did a six-month stint on the space station. Speaking after the launch, he said Furukawa's mission could serve to lift his country's spirits after the earthquake that earlier this year devastated swathes of Japan.

"Now in Japan, there is not a lot of good news around, but I hope that by seeing Satoshi going up, the young people can feel they have a better future," Noguchi said.

Upon docking at the station, the crew will join the current station members — Garan and Russian cosmonauts Andrei Borisenko and Alexander Samokutyayev.

This is the second run for the upgraded digital model of the Soyuz, which has served as the workhorse of the Russian space program for decades.

While aboard the ISS, the team will witness the final mission of the U.S. shuttle, with NASA retiring the 30-year program after Atlantis flies on July 8.

The mothballing of the shuttle evokes a palpable sense of melancholy among U.S. space professionals, and a comparable degree of pride among Russians, who will be picking up the slack.

"Where five years ago we were launching just two (manned) craft every year, as of last year, we have started launching four crafts," said Sergei Krikalyov, who heads Russia's Star City cosmonaut training center.

Patrick Buzzard, NASA's representative to Russia, said the two countries have relied on one another over the recent history of space exploration and that nothing was set to change.

"It is such a strong partnership and we have these capabilities that everyone brings to the table. That makes it a more robust program," Buzzard said.

While NASA devises ways to replace its shuttle fleet, the privately run California-based space transportation company SpaceX is developing the Dragon craft that NASA hopes could offer it another, possibly less costly, alternative.

The $56 million price that the Russian Space Agency charges NASA to send up astronauts is set to go up to $63 million per passenger from 2014. A recent contract extension with the agency totaled $753 million and covered trips for a dozen NASA astronauts from 2014 through 2016.

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