• 2010 nasa special
    a total eclipse of the Sun is visible from within a narrow corridor that traverses Earth's southern Hemisphere. The path of the Moon's umbral shadow crosses the South Pacific Ocean where it makes no landfall except for Mangaia (Cook Islands) and Easter Island (Isla de Pascua).

Mission Management Team Approves Thursday Launch

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Today’s Mission Management Team meeting has concluded. The team is unanimous to go forward with space shuttle Discovery’s launch tomorrow at 4:50 p.m. EST.

The prelaunch news conference is scheduled to begin at 11 a.m. on NASA Television. The participants will be Mike Moses, Mission Management Team chair, Mike Leinbach, shuttle launch director, Scott Higginbotham, STS-133 payload manager, and Kathy Winters, shuttle weather officer.

Watch the news conference live at http://www.nasa.gov/ntv

NASA Managers: It's a "Go" for Launch

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At today's pre-launch news conference NASA's mission management team have given their unanimous approval for space shuttle Discovery's launch tomorrow at 4:50 p.m. EST.

"Everything is on track and going beautifully with the countdown," said Mike Moses, mission management team chair. "We're really looking forward to a very action-packed, successful mission and everything is on track."

Mike Leinbach, shuttle launch director, agreed that everything is going extremely well with the launch countdown. He also acknowledged the processing teams who worked on Discovery, its flight systems and ground elements. "As we're powering up (the systems) we're seeing no problems at all."

The rotating service structure will be rolled away from Discovery at around 8 p.m. revealing it for the last time on the launch pad. Loading of the external fuel tank will begin at around 7:25 a.m. tomorrow morning. "We're not tracking any issues and it looks like Discovery will fly this time," said Leinbach.

Kathy Winters, shuttle weather officer, reported that the weather remains exceptional with only a 20 percent chance that weather will be prohibitive at launch time. The only slight issue may be a localized off-shore shower in the late afternoon. The forecast during tanking also is looking very good.

At 7:15 a.m. EST NASA TV will begin coverage of the fueling of the external tank. Launch coverage for Discovery's final mission to the International Space Station will begin at 11:30 a.m.

Rotating Service Structure Opens For Launch

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The rotating service structure (RSS) on NASA Kennedy Space Center’s Launch Pad 39A moved away from space shuttle Discovery in preparation for tomorrow's launch attempt. The move began at 8:02 p.m. EST and was completed at 8:37 p.m. Moving the structure, which is used for weather protection and provides access to the shuttle at the pad, took about 30 minutes.‬

Teams are not working any issues that would delay liftoff at 4:50 p.m.

Fueling of Discovery's external fuel tank with more than 535,000 gallons of super cold liquid hydrogen and oxygen is expected to begin at approximately 7:25 a.m. NASA TV coverage begins at 7:15 a.m.

A Nebula by Any Other Name

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Nebulae are enormous clouds of dust and gas occupying the space between the stars. Some have pretty names to match their good looks, for example the Rose nebula, while others have much more utilitarian names. Such is the case with LBN 114.55+00.22, seen here in an image from NASA's Wide-field Infrared Survey Explorer, or WISE.

Named after the astronomer who published a catalogue of nebulae in 1965, LBN stands for "Lynds Bright nebula." The numbers 114.55+00.22 refer to nebula's coordinates in our Milky Way galaxy, serving as a sort of galactic home address.

Astronomers classify LBN 114.55+00.22 as an emission nebula. Unlike a reflection nebula, which reflects light from nearby stars, an emission nebula emits light. Emission nebulae are usually found in the disks of spiral galaxies, and are places where new stars are forming.

The colors used in this image represent specific wavelengths of infrared light. Blue and cyan represent light emitted at wavelengths of 3.4 and 4.6 microns, which is predominantly from stars. Green and red represent light from 12 and 22 microns, respectively, which is mostly emitted by dust.

Image Credit: NASA/JPL-Caltech/UCLA

SDO Celebrates One Year Anniversary

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the Solar Dynamics Observatory (SDO) is launched into space on an Atlas V-401 from Cape Canaveral.

One year ago, on February 11, 2010, at 10:23 in the morning, SDO launched into space on an Atlas V-401 from Cape Canaveral. Credit: NASA On February 11, 2010, at 10:23 in the morning, NASA's Solar Dynamics Observatory (SDO) launched into space on an Atlas rocket from Cape Canaveral. A year later, SDO has sent back millions of stunning images of the sun and a host of new data to help us understand the complex star at the heart of our solar system.

"One of the highlights of the last year is just that everything worked so smoothly," says astrophysicist Dean Pesnell, the project scientist for SDO at NASA's Goddard Space Flight Center in Greenbelt, Md. "We turned it on in March and it immediately started sending us data at 150 megabits per second. It worked from the very get go."

The first things scientists and the public saw from SDO was an array of wonderfully detailed pictures of the sun. One of the three instruments on board, called the Atmospheric Imaging Assembly (AIA), captures a shot of the sun every 12 seconds in 10 different wavelengths -- each wavelength helps illuminate aspects of the sun at different temperatures. The images are all available in real time online for everyone to see.

"It's been great to watch how popular these images are," says Phil Chamberlin, another astrophysicist at Goddard and one of SDO's deputy project scientists. "The public has been extremely interested. And it's important that people see what the sun is doing and how it affects us."

A solar eruptive prominence as seen in extreme UV light on March 30, 2010 with Earth superimposed for a sense of scale.
Here is one of the first images taken by SDO and still a favorite: A solar eruptive prominence as seen in extreme UV light on March 30, 2010 with Earth superimposed for a sense of scale. Credit: NASA/SDO

These images have regularly caught solar flares, coronal mass ejections, filament eruptions and other space weather phenomena in the act. Such images are helping to flesh out such questions as why the sun's corona – its atmosphere – is thousands of times hotter than the surface of the sun. For example, given how quickly SDO takes its pictures, scientists were recently able to track plumes of plasma heating up as they moved from the sun's surface up into the corona.

Another fruitful area of research from SDO involves understanding the massive explosions on the sun's surface called solar flares. Scientists have been able to use the GOES spacecraft to look at X-rays emitted from solar flares for some 40 years. But observing them in X-rays means one can only see those parts of the flares that are about 10 million degrees Celsius. Other spacecraft have since shown the flares in other wavelengths, but SDO's ability to provide detailed images of the same event in so many wavelengths allows one to see different parts of the flare no matter what temperature. It now appears that flares may be more complex than previously known.

The other two instruments onboard SDO also have made a strong impact. The Extreme Ultraviolet Variability Experiment (EVE) examines the extreme ultraviolet photons from the sun that are responsible for heating in Earth's upper atmosphere. The Helioseismic and Magnetic Imager (HMI) observes how the magnetic fields across the surface of the sun change, as well as seismic activity across the sun. "These are the doorway to the interior of the sun," says Pesnell. "This is how we understand what's going on inside it."

Artist rendition of SDO spacecraft. 

Artist's concept of the Solar Dynamics Observatory. Credit: NASA/Goddard Space Flight Center Conceptual Image Lab One of SDO's greatest successes so far may be how well these three instruments coordinate with other spacecraft observing the sun. For example, the two STEREO spacecraft moved into position on opposite sides of the sun on February 6, 2011 and will continue towards the far side and all the way around again over the next eight years. For that entire time, STEREO and SDO together will offer scientists their first opportunity to watch the entire sun simultaneously. There are many clues that solar weather can be connected over distances up to a million miles, but this will be the first chance to see how flares on one side coordinate with flares on the other.

In addition, sun observers such as the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) can show the highest energy, highest temperature bursts on the sun. These can be overlaid on SDO's images to get a more comprehensive picture of each individual event. On January 28, 2011, for example, two bursts of plasma jumped out from each side of the sun simultaneously -- an example of unconfirmed theories that such things often happen 180 degrees apart. Luckily, RHESSI caught the same event in its images, offering an unprecedented chance to examine all parts of the bursts at all temperatures.

"It's not just SDO. It's RHESSI, STEREO, SDO's three instruments all together," says Chamberlin. "The whole is much greater than the sum of the individual parts. We've been talking about putting together this great Heliophysics observatory and this really is what we have."

A composite SDO image from Feb. 11, 2011, exactly one year after its launch.  
 
A composite SDO image from Feb. 11, 2011, exactly one year after its launch. The image combines three wavelengths of extreme ultraviolet light. Credit: NASA/SDO

SDO is the first mission in a NASA science program called Living With a Star, the goal of which is to develop the scientific understanding necessary to address those aspects of the sun-Earth system that directly affect our lives and society. NASA Goddard built, operates, and manages the SDO spacecraft for NASA's Science Mission Directorate in Washington.

For more information about SDO, visit: www.nasa.gov/sdo.

Five Things About NASA's Valentine's Day Comet

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Artist concept of Stardust-NExT and comet Tempel 1 covered in chocolate for the spacecraft's encounter on February 14, 2011. 

The planned Valentine's Day (Feb. 14, 2011) rendezvous between NASA's Stardust-NExT mission and comet Tempel 1 inspired this chocolate-themed artist's concept. Image credit: NASA/JPL-Caltech
 
 
Here are five facts you should know about NASA's Stardust-NExT spacecraft as it prepares for a Valentine's "date" with comet Tempel 1. Feel free to sing along! 

1. "The Way You Look Tonight" – The spacecraft is on a course to fly by comet Tempel 1 on Feb. 14 at about 8:37 p.m. PST (11:37 p.m. EST) -- Valentine's Day. Time of closest approach to Tempel 1 is significant because of the comet's rotation. We won't know until images are returned which face the comet has shown to the camera. 

2. "It's All Coming Back To Me Now" – In 2004, Stardust became the first mission to collect particles directly from a comet, Wild 2, as well as samples of interstellar dust. The samples were returned in 2006 via a capsule that detached from the spacecraft and parachuted to the ground at a targeted area in Utah. Mission controllers then placed the still-viable Stardust spacecraft on a flight path that could reuse the flight system, if a target of opportunity presented itself. Tempel 1 became that target of opportunity. 

3. "The First Time Ever I Saw Your Face" – The Stardust-NExT mission will allow scientists for the first time to look for changes on a comet's surface that occurred after one orbit around the sun. Tempel 1 was observed in 2005 by NASA's Deep Impact mission, which put an impactor on a collision course with the comet. Stardust-NExT might get a glimpse of the crater left behind, but if not, the comet would provide scientists with previously unseen areas for study. In addition, the Stardust-NExT encounter might reveal changes to Tempel 1 between Deep Impact and Stardust-Next, since the comet has completed an orbit around the sun. 

4. "The Wind Beneath My Wings" – This Tempel 1 flyby will write the final chapter of the spacecraft's success story. The aging spacecraft approached 12 years of space travel on Feb. 7, logging almost 6 billion kilometers (3.5 billion miles) since launch. The spacecraft is nearly out of fuel. The Tempel 1 flyby and return of images are expected to consume the remaining fuel. 

5. "Love is Now the Stardust of Yesterday" – Although the spacecraft itself will no longer be active after the flyby, the data collected by the Stardust-NExT mission will provide comet scientists with years of data to study how comets formed and evolved.
Bonus points for naming all the artists who sing these catchy tunes.

Heading Into the Bonus Round – in Space

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Artist concept of NASA's Stardust-NExT mission 


Artist's concept of NASA's Stardust-NExT mission, which will fly by comet Tempel 1 on Feb. 14, 2011.
Image credit: NASA/JPL-Caltech/LMSS
A bonus round is something one usually associates with the likes of a TV game show, not a pioneering deep space mission. "We are definitely in the bonus round," said Stardust-NExT Project Manager Tim Larson of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "This spacecraft has already flown by an asteroid and a comet, returned comet dust samples to Earth, and now has almost doubled its originally planned mission life. Now it is poised to perform one more comet flyby."
A Successful Prime Mission
NASA's Stardust spacecraft was launched on Feb. 7, 1999, on a mission that would explore a comet as no previous mission had. Before Stardust, seven spacecraft from NASA, Russia, Japan and the European Space Agency had visited comets – they had flight profiles that allowed them to perform brief encounters, collecting data and sometimes images of the nuclei during the flyby.
Like those comet hunters before it, Stardust was tasked to pass closely by a comet, collecting data and snapping images. It also had the ability to come home again, carrying with it an out-of -this-world gift for cometary scientists – particles of the comet itself. Along the way, the telephone booth-sized comet hunter racked up numerous milestones and more than a few "space firsts."
In the first round of its prime mission, Stardust performed observations of asteroid Annefrank, only the sixth asteroid in history to be imaged close up. After that, Stardust racked up more points of space exploration firsts. It became the first spacecraft to capture particles of interstellar dust for Earth return. It was first to fly past a comet and collect data and particles of comet dust (hurtling past it at almost four miles per second) for later analysis. Then, it was first to make the trip back to Earth after traveling beyond the orbit of Mars (a two-year trip of 1.2 billion kilometers, or 752 million miles). When Stardust dropped off its sample return capsule from comet Wild 2, the capsule became the fastest human-made object to enter Earth's atmosphere. The mission was also the first to provide a capsule containing cometary dust specimens, speciments that will have scientists uncovering secrets of comets for years to come.
With such a high tally of "firsts" on its scoreboard, you'd think Stardust could receive a few parting gifts and leave the game. And an important part of the original spacecraft is currently enjoying retirement – albeit a high-profile one: Stardust's 100-pound sample return capsule is on display in the main hall (Milestones of Flight) of the Smithsonian's National Air and Space Museum in Washington. But the rest of NASA's most-seasoned comet hunter is still up there – and there is work still to be done.
"We placed Stardust in a parking orbit that would carry it back by Earth in a couple of years, and then asked the science community for proposals on what could be done with a spacecraft that had a lot of zeros on its odometer, but also had some fuel and good miles left in it," said Jim Green, director of NASA's Planetary Science Division.
Moving into the Bonus Round
In January 2007, from a stack of proposals with intriguing ideas, NASA chose Stardust-NExT (Stardust's Next Exploration of Tempel). It was a plan to revisit comet Tempel 1 at a tenth of the cost of a new, from-the-ground-up mission. Comet Tempel 1 was of particular interest to NASA. It had been the target of a previous NASA spacecraft visit in July 2005. That mission, Deep Impact, placed a copper-infused, 800-pound impactor on a collision course with the comet and observed the results from the cosmic fender-bender via the telescopic cameras onboard the larger part of Deep Impact, a "flyby" spacecraft observing from a safe distance.
"The plan for our encounter is to be more hospitable to comet Tempel 1 than our predecessor," said Joe Veverka, principal investigator of Stardust-NExT from Cornell University in Ithaca, N.Y. "We will come within about 200 kilometers [124 miles] of Tempel 1 and view the changes that took place over the past five-and-a-half years."
That period of time is significant for Tempel 1 -- it is the period of time it takes the comet to orbit the sun once. Not much happens during a comet's transit through the chilly reaches of the outer solar system. But when it nears perihelion (the point in its orbit that an object, such as a planet or a comet, is closest to the sun), things begin to sizzle.
"Comets can be very spectacular when they come close to the sun, but we still don't understand them as well as we should," said Veverka. "They are also messengers from the past. They tell us how the solar system was formed long ago, and Stardust-NExT will help us understand how much they have changed since their formation."
So the spacecraft that had traveled farther afield than any of its predecessors was being sent out again in the name of scientific opportunity. In between spacecraft and comet lay four-and-a-half years, over a billion kilometers (646 million miles), and more than a few hurdles along the way.
Your Mileage May Vary
"One of the challenges with reusing a spacecraft designed for a different prime mission is you don't get to start out with a full tank of gas," said Larson. "Just about every deep-space exploration spacecraft has a fuel supply customized to get the job done, with some held in reserve for contingency maneuvers and other uncertainties. Fortunately, the Stardust mission navigation team did a great job, the spacecraft operated extremely well, and there was an adequate amount of contingency fuel aboard after its prime mission to make this new comet flyby possible – but just barely."
Just how much fuel is in Stardust's tanks for its final act?
"We estimate we have a little under three percent of the fuel the mission launched with," said Larson. "It is an estimate, because no one has invented an entirely reliable fuel gauge for spacecraft. There are some excellent techniques with which we have made these estimates, but they are still estimates."
One of the ways mission planners can approximate fuel usage is to look at the history of the vehicle's flight and how many times and for how long its rocket motors have fired. When that was done for Stardust, the team found their spacecraft's attitude and translational thrusters had fired almost half-a-million times each over the past 12 years.
"There is always a little plus and minus with each burn. When you add them all up, that is how you get the range of possible answers on how much fuel was used," said Larson.
Fuel is not the only question that needs to be addressed on the way to a second comet encounter. Added into the mix is the fact a comet near the sun can fire off jets of gas and dust that can cause a change in its orbit, sometimes in unexpected ways, potentially causing a precisely designed cometary approach to become less precise. Then there are the distances involved. Stardust will fly past comet Tempel 1 on almost the opposite side of the sun from Earth, making deep-space communication truly, well, deep space. Add into the mix the Stardust spacecraft itself. Launched when Bill Clinton was in the White House, Stardust has been cooked and frozen countless times during its trips from the inner to outer solar system. It has also weathered its fair share of radiation-packed solar storms. But while its fuel tank may be running near-empty, that doesn't mean Stardust doesn't have anything left in the tank.
"All this mission's challenges are just that – challenges," said Larson. "We believe our team and our spacecraft are up to meeting every one of them, and we're looking forward to seeing what Tempel 1 looks like these days."
The Final Payoff
Larson, Veverka and the world will get their chance beginning a few hours after the encounter on Monday, Feb. 14, at about 8:56 p.m. PST (11:56 p.m. EST), when the first of 72 bonus-round images of the nucleus of comet Tempel 1 are downlinked.
All images of the comet will be taken by the spacecraft's navigation camera – an amalgam of spare flight-ready hardware left over from previous NASA missions: Voyager (launched in 1977), Galileo (launched in 1989), and Cassini (launched in 1997). Each image will take about 15 minutes to transmit. The first five images to be received and processed on the ground are expected to include a close up of Tempel 1's nucleus. All data from the flyby (including the images and science data obtained by the spacecraft's two onboard dust experiments) are expected to take about 10 hours to reach the ground.
Stardust-NExT is a low-cost mission that will expand the investigation of comet Tempel 1 initiated by NASA's Deep Impact spacecraft. JPL, a division of the California Institute of Technology in Pasadena, manages Stardust-NExT for the NASA Science Mission Directorate, Washington, D.C. Joe Veverka of Cornell University, Ithaca, N.Y., is the mission's principal investigator. Lockheed Martin Space Systems, Denver Colo., built the spacecraft and manages day-to-day mission operations.
More information about Stardust-NExT is online at: http://stardustnext.jpl.nasa.gov .

Charles Bolden's Story: "From the Segregated South to Low Earth Orbit"

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It's a long way from the segregated south to low Earth orbit. But I am fortunate to have made the journey and to have had many opportunities to serve my nation in a 34-year career with the U.S. Marine Corps and in many roles at NASA, currently as head of the nation's space program.
When I was a young man, my service as NASA's first African American 
Administrator under the Nation's first Black president would have been nearly 
unthinkable. 

But through the efforts of many people of all races, our nation has changed. 
And, thanks to the Space Shuttle Program, and NASA's cross-disciplinary 
exploration missions, African Americans and many others have had access to 

space and also to science and technological careers. The shuttle was really 
instrumental in breaking the color barrier for African Americans in space, and 
it all happened without a single law being passed.

 


Today, African Americans are scientists, engineers, and astronauts. They're developing instruments for spacecraft to peer beyond the edge of our solar system and opening solar arrays on the International Space Station with just a tether holding them to a vehicle moving nearly 17,000 miles per hour. NASA is reinvigorating its focus on research and development to develop technologies that don't exist today. We will send humans farther and faster into space. We'll visit places we've never been, with people and robots, launch science missions to uncover unfathomable secrets of the universe, and make air travel safer and cleaner here on the home front. African Americans have been, and will continue to be, key to all of these efforts.


I might never have had a chance in space were it not for the late great Ron McNair, another African American pioneer in exploration who encouraged me to apply to the astronaut corps. I was being a naysayer, thinking there was no way I would be accepted. But Ron persisted, and I am grateful to him to this day and for all of the life and professional learning he shared with me in his too-short time before he was lost in the Space Shuttle Challenger tragedy. Ron was my "Sputnik moment."

Since America's "Sputnik moment," when the nation stood up and took notice, and made a decision to commit to exploration and the technology development and innovation that would be required, many African Americans have given their heart and soul to the space program. The list is long at NASA. Astronauts like Guion S. Bluford, Dr. Mae Jemison, Frederick D. Gregory, and Dr. Ronald McNair and Michael P. Anderson, to name just a few, pioneered a path in space. Similarly, scientists like astrochemist Dr. Emmett Chappelle, who was inducted into the National Inventors Hall of Fame, and Dr. George Carruthers, who helped our Apollo missions be more than just flags and footprints, and Dr. Harriett Jenkins, who helped diversify the agency as head of its Equal Employment Programs, made vital contributions to the space program. Without the historic contributions of these and many others, NASA would not be the agency it is today.

For my part, my parents were probably the biggest influences on my life. Not only growing up, but still, today, as I make decisions as a husband, grandfather, father, brother and leader. My father was a teacher, my mother a librarian. Learning was always at the forefront of our lives as well as a commitment to public service. That led me to the military and a chance to serve my country as my father and my uncles had done in World War II when Blacks had to fight for the right to serve in our Armed Forces.  I wanted to follow in the footsteps of so many African Americans who had already served this country with distinction, if not always with recognition.

For me, it was an uphill battle. Because of my race, no one in my South Carolina congressional delegation would provide an appointment nor nomination to the Academy as was required for admission. I wrote President Johnson asking for help, and that's when Congressman William Dawson of Illinois provided me the appointment I needed to be accepted. Rep. Dawson was himself a veteran of World War I, and only the third African American elected to Congress in the 20th century. He was the only serving Black member during his first term.

Since then, I graduated from the U.S. Naval Academy, flew more than 100 combat missions over Vietnam, earned a master's degree in systems management, flew on the Space Shuttle four times, and rose to the rank of Major General in the U.S. Marine Corps.

It has been quite a ride, but I couldn’t have done it without all those who came before. That's why I tell today's young people that I hope they will take the gains that previous generations have made and make their own progress. Students ask me how to become an astronaut.  I tell them to pursue any of the paths in science, technology, engineering and mathematics and their chances of a strong, secure career that makes contributions to our economy and improves life for people worldwide will be possible.

When I speak to young people, I tell them, don't waste your time trying to explain yourself or your identity to anyone or justify why you are where you are -- in the workplace or anywhere else. Do your job and do it very well. Live your life according to the Golden Rule and the strong principles taught by Dr. Martin Luther King, Jr.  Always remind yourself of 'why' you are pursuing the things you do. Stay in touch with that answer, and don't let others define it for you.
A touchstone of my personal philosophy is these words from Rev. Dr. Benjamin E. Mays, Dr. King's mentor during his years of study at Morehouse College.  It is Dr. Mays who perhaps influenced Dr. King most, and whose words and thoughts we frequently heard reflected in the words of Dr. King.  This is from a sermon by Dr. Mays titled "What Man Lives By":  
Man must believe that however hard the road, however difficult today, tomorrow things will be better.  Tomorrow may not be better, but we must believe that it will be.  Wars may never cease, but we must continue to strive to eliminate them.  We may not abolish poverty, but we must believe that we can provide bread enough to spare for every living creature and that we can find the means to distribute it.  We may not exterminate racism, but we must believe that different racial groups can live together in peace, and we must never cease to try to build a society in which the fatherhood of God and the brotherhood of man become realities.
I never really left Columbia, Soth Carolina behind. The family and teachers and friends that are still there remind me of who I am, where I come from, and what my ideals should be. It was a fortunate upbringing in many ways, despite the hardships. I wouldn't change a thing. And despite what some might say, the future is bright for the young people just entering the workforce today. I hope I have had some small part in the progress this nation has made. I look forward to the space program's continued success improving people's lives around the world through new technologies and discoveries and showing that with innovation, creativity and passion, you can knock down any barrier of race, ethnicity, creed, or gender.

NASA startling discovery: 54 planets found that could harbor life Continue reading on Examiner.com: NASA startling discovery: 54 planets found that could harbor life - Miami Technology | Examiner.com http://www.examiner.com/technology-in-miami/nasa-startling-discovery-54-planets-found-that-could-harbor-life#ixzz1DRBHXa6C

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The South Florida spaceplanetary community got news for cheering about: The Kepler mission is making science fiction a reality. In a single year, they spotted 235 thousand candidates for confirmation as planets. Of these, sixty-eight measure the same as Earth, fifty-four could harbor life and five are the Earth size. Add a new Solar system-like discovery with six planets orbiting a star.

Barriers are Breaking down: The results reported at a NASA press conference on Wednesday were based on observations by probing made from  May through September 2009, in which 150,000 stars were observed, the equivalent to one fourth the sky. William Borucki, at Ames Research Center in Moffett Field, California, said, "That we found so many candidates for planets in so little of the sky, suggests that there are countless planets orbiting Sun-like stars in our galaxy.” He added, “We went from zero to sixty-eight planet candidate Earth size and from zero to fifty-four candidates in the habitable zone; they could have moons with liquid water.”

The fifty-four are in the "habitable zone," where liquid water could exist on the planetary surface, thereby increasing the life possibilities in all its forms.  Furthermore, theirs compositions are so varied that some have a density as light as Styrofoam and others are similar to iron. The Earth density is between these ranges. Of The 235 thousand potential candidates, sixty-eight could measure the same as our planet; 288 would be super-Earth; 662 would measure the same as Neptune; 165 same as Jupiter, and 19 would exceed the jovial planet size. All the data has to be reanalyzed and verified by scientists at NASA.

Charles Bolden from NASA said, “These conclusions underscore the importance of Space Agency's science missions, which systematically increase our understanding of our place in the cosmos." Before the Keplers announcement on Wednesday, the number of planets outside the solar system, known as exoplanets, was 519. That means that Kepler could triple the known planets number. Launched in 2009, the telescope has been orbiting the sun between Earth and Mars; it has conducted a global survey, looking for planets similar to Earth all year. It has discovered many planets much smaller than Jupiter, the largest of our solar system, and giant planets, totaling 15 new mega planets.

Kepler is providing one-hundred times more information than before. It is discovering a variability of stars that had never been analyzed, like planets as small as they had never been imagined,” said Mr. Borucki, the principal investigator for the Kepler mission. More than two-hundred celestial bodies have not yet been confirmed as planets, but Borucki estimated that most of them will qualify. He went on, “In one generation we went from the idea of alien planets as a pillar of science fiction to present, when Kepler has helped make science fiction a reality.

Step by step.  Debra Fischer, expert on exoplanets at Yale University, not a Kepler team member, but an external consultant for NASA, said the new information “gives us a much firmer basis, hoping to discover life in other worlds.”  “I feel better now knowing these new Kepler results than a week ago,” she said. All Kepler research stars are in our galaxy, but are so far that traveling to them is not realistic. It would take us a million years to reach them with our current technology. What excites astronomers is that the more planets there are, with the right conditions, the greater the chances of life existing in other worlds.

Continue reading on Examiner.com: NASA startling discovery: 54 planets found that could harbor life - Miami Technology

Among 1,200 Possible Planets, Some Seem Like Our Own

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An artist's idea of what Kepler-11 would look like. Six planets orbit the sun-like star  

SHIRLEY GRIFFITH: And I’m Shirley Griffith with EXPLORATIONS in VOA Special English. Today we tell about an American spacecraft that has a date with a comet. We hear the latest about a space shuttle commander whose wife continues to recover from a deadly gun attack. And we remember a sad anniversary. But first, the discovery of possible planets like our own.
STEVE EMBER: Last week, American space agency scientists announced the discovery of possible Earth-like planets. The announcement came from newly released information from the Kepler space-based telescope.

The researchers say six new planets have been confirmed. But the Kepler mission’s chief scientist, William Borucki, says eighty percent of the possible planets will probably be confirmed in the coming months and years.

Before last week’s announcement, the total number of so-called exoplanets outside our solar system was just over five hundred. Mr. Borucki says that number increased, based on new information from the small part of the sky examined by the Kepler telescope.

WILLIAM BORUCKI: “Kepler looks at one-four-hundredth of the sky. If we had four hundred of these fields of view, we would see four hundred times that number of candidates.”
SHIRLEY GRIFFITH: Mr. Borucki notes that they have found many possible planets in a small part of the sky. This suggests that there are countless planets orbiting stars like our sun in our galaxy. He says there must be millions of planets orbiting the stars that surround our sun.

Mr. Borucki says he was surprised to find sixty-eight suspected planets about the size of Earth or smaller. Fifty-four of the possible exopla on the planet’s surface. He says some of the possible planets could even have moons with liquid wable area of their parent stars.

STEVE EMBER: NASA scientists using the Kepler space telescope also announced the discovery of six planets orbiting a star called Kepler-11. Investigator Jack Lissauer described the discovery.
JACK LISSAUER: “Kepler 11 is a surprising flat and compact system of six transiting planets. The five inner planets are especially close together, something that we didn’t think would happen for worlds of this size.”

NASA says Kepler-11 has the fullest, most compact planetary system yet discovered beyond our own. Mr. Lissauer says the five inner planets areases, possibly including water ice.

The Kepler space telescope looks for planets by measuring tiny decreases in the brightness of stars when planets cross in front of them. Scientists
non-professional astronomers around the world are helping study the new information about the possible planets. They are doing this on an Internet website called PlanetHunters.org.


SHIRLEY GRIFFITH: A spacecraft from the United States space agency has a date with comet Temple 1 on February fourteenth. The Stardust-NExT spacecraft is to meet the comet on Valentine’s Day. This is the day when many people will be going out on a date with someone special in their lives.

This meeting is all the more meaningful because comet Temple 1 has been visited before. And scientists are very interested in seeing how this solar system
of ice and rock that leave behind a trail of gas and dust in space as they approach the sun’s warming light.
Sometimes, observers see this as a comet’s tail, which can be visible to the unaided eye stretching across the night sky.

On February fourteenth, Stardust will approach to within two hundred kilometers of comet Temple 1. The spacecraft will take seventy-two high quality pictures of the comet’s nucleus, which is about six kilometers across. But this is not the first time that Temple 1 has been observed closely.

STEVE EMBER: In two thousand five, another NASA spacecraft called Deep Impact paid a visit to Temple 1. It released a small device, or probe, that crash
The main Deep Impact spacecraft was able to send back information to scientists on Earth. They found evidence of carbon-based chemicals, sand and, most importantly, water ice. Scientists will have a second look at comet Temple 1 with Stardust. This doule take is something new for comet experts.

SHIRLEY GRIFFITH: Joe Veverka is principal investigator of Stardust-NExT. He says it will give scientists their first chance to see how comets change with each close approach to the sun.
JOE VEVERKA: “We know that comets lose material, ut the question is, ‘How much does the surface change and where does the surface change?’ So we’ll be able to answer that question by comparing our images with those taken by Deep Impact in 2005.”

STEVE EMBER: Astronomers have known about Comet Temple 1 for a long time. They discovered it in eighteen sixty-seven. They have observed it ost of its returns  the inner solar system since then.It is a short-period comet. This means it orbits the sun in a relatively short time. For Temple 1, that is about five and a half years.

Where does the comet go when it is not close to the sun? Short-period comets like Temple 1 have orbits that take them only as far as the outer planets like Jupiter. In fact, Temple 1 is a member of the Jupiter family of comets. These are all influenced by vity of the solar system’s largest planet. Long-period comets, however, may take several hundred years to orbit the sun.

SHIRLEY GRIFFITH: Scientists t water and carbon compounds to Earth. That means they may have supplied the Earth with the basic building blocks of life nearly four billion years ago. That is a big reason why scientists are so interested in them.


STEVE EMBER: Late last week, NASA said astronaut Mark Kelly would return to train with crewmembers on the last flight of the space shuttle Endeavor in April. Mark Kelley is the husband of United States Representative Gabrielle Giffords of Arizona. A shot her in the head on January eighth at a political gathering in Tuscon, Arizona. Six people were killed in the attack, including a young girl and a federal judge.


Congresswoman Gabrielle Giffords and Mark Kelly in April of last year

Congresswoman Gabrielle Giffords and Mark Kelly in April of last year
Gabrielle Giffords has since beea hospital in Houston, Texas. Astronaut Mark Kelly trains at the Johnson Space Center in that city.

Recently Mr. Kelly said he plans to command the final flight of the Endeavor. He said he hopes his wife Gabrielle Giffords will be at the launch. Mr. Kelly’s brother, Scott Kelly, is the current commander of the International Space Station. NASA plans to retire the space shuttle program this year.
(SOUND)
SHIRLEY GRIFFITH: On January twenty-eighth, nineteen eighty-six, tragedy struck NASA’s Space Shuttle program.


It was only seventy-three seconds into the twenty-fifth flight for the program. A problem with one of its booster rockets caused space shuttle Challenger to explode. Seven astronauts were killed. Many Americans clearly remember the event as terday. Students were watching the launch from their classrooms. One of the astronauts was Christa McAuliffe, a school teacher.
two thousand three, another accident on the space shuttle Columbia claimed the lives of seven more astronauts.


STEVE EMBER: Valerie Neal supervises the human spaceflight collection at the Smithsonian National Air and Space Museum in Washington, D.Cbecause spaceflight is experimental, it continues to be risky. But Ms. Neal says the United States space program always seems to recover from hardship.

VALERIE NEAL: “The fact, though, that the space shuttle program didn’t close down, that we didn’t close up shop and say, ‘This is too
SHIRLEY GRIFFITH: This program was written and produced by Mario Ritter. I’m Shirley Griffith.

STEVE EMBER: And I’m Steve Ember. Join us again next week for EXPLORATIONS in VOA Special English.

Test Firing the First Aerojet AJ26 Engine

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NASA Administrator Charlie Bolden (left) and Stennis Space Center Director Patrick Scheuermann view a test firing of the first Aerojet AJ26 flight engine.

NASA Administrator Charlie Bolden (left) and Stennis Space Center Director Patrick Scheuermann view a test firing of the first Aerojet AJ26 flight engine. Once flight acceptance is achieved, the engine will power the first stage of Orbital’s Taurus II space launch vehicle on commercial cargo missions to the International Space Station. NASA has partnered with Orbital to provide eight cargo missions to the space station, with the first scheduled for early 2012.

Image Credit: NASA/Danny Nowlin

NASA Astronaut Mark Kelly Resumes Training For STS-134 Mission

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HOUSTON -- NASA astronaut Mark Kelly will resume training as commander of the STS-134 space shuttle mission on Monday, Feb. 7. With the exception of some proficiency training, Kelly has been on personal leave since Jan. 8 to care for his wife, congresswoman Gabrielle Giffords, who was critically wounded in a Tucson, Ariz. shooting.

"I am looking forward to rejoining my STS-134 crew members and finishing our training for the mission," Kelly said. "We have been preparing for more than 18 months, and we will be ready to deliver the Alpha Magnetic Spectrometer (AMS) to the International Space Station and complete the other objectives of the flight. I appreciate the confidence that my NASA management has in me and the rest of my space shuttle crew."

"We are glad to have Mark back," said Peggy Whitson, chief of the Astronaut Office at NASA's Johnson Space Center in Houston. "He is a veteran shuttle commander and knows well the demands of the job. We are confident in his ability to successfully lead this mission, and I know I speak for all of NASA in saying 'welcome back'.

A news briefing will be held at 2 p.m. CST today at Johnson to discuss Kelly's return. The briefing will be broadcast on NASA Television.

Questions will be taken from reporters at Johnson, NASA Headquarters and the Kennedy Space Center in Florida.

Participants will include:
-- Mark Kelly, commander, STS-134
-- Peggy Whitson, chief, Astronaut Office
-- Brent Jett, chief, Flight Crew Operations Directorate

Because of winter weather conditions, Johnson will be closed until noon. However, the Johnson newsroom at 281-483-5111 is staffed to receive calls from journalists requesting credentials.

On Monday, Feb. 7, NASA TV will broadcast video b-roll of Kelly's first training session with his crew at 11:30 a.m. CST. Additional b-roll of his first day of training will air at 3 p.m. The training sessions will not be available for filming by news media.
Astronaut Rick Sturckow, the backup commander for the mission, will resume his role as the deputy chief of the Astronaut Office. For more information about the STS-134 mission and crew, visit:

http://www.nasa.gov/shuttle

First Ever STEREO Images of the Entire Sun

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Latest image of the far side of the Sun based on high resolution STEREO data, taken on February 2, 2011 at 23:56 UT.

Latest image of the far side of the Sun based on high resolution STEREO data, taken on February 2, 2011 at 23:56 UT when there was still a small gap between the STEREO Ahead and Behind data. This gap will start to close on February 6, 2011, when the spacecraft achieve 180 degree separation, and will completely close over the next several days. Credit: NASA

February 6, 2011: It's official: The sun is a sphere.

On Feb. 6th, NASA's twin STEREO probes moved into position on opposite sides of the sun, and they are now beaming back uninterrupted images of the entire star—front and back.

"For the first time ever, we can watch solar activity in its full 3-dimensional glory," says Angelos Vourlidas, a member of the STEREO science team at the Naval Research Lab in Washington, DC.

NASA released a 'first light' 3D movie on, naturally, Super Bowl Sunday:

 
The solar sphere as observed by STEREO and the Solar Dynamics Observatory on January 31, 2011. Because the STEREO separation was still slightly less than 180o at that time, a narrow gap on the far side of the Sun has been interpolated to simulate the full 360o view. The gap and quality of farside imaging will improve even more in the days and weeks ahead.


"This is a big moment in solar physics," says Vourlidas. "STEREO has revealed the sun as it really is--a sphere of hot plasma and intricately woven magnetic fields."

Each STEREO probe photographs half of the star and beams the images to Earth. Researchers combine the two views to create a sphere. These aren't just regular pictures, however. STEREO's telescopes are tuned to four wavelengths of extreme ultraviolet radiation selected to trace key aspects of solar activity such as flares, tsunamis and magnetic filaments. Nothing escapes their attention.

An artist rendering of the twin STEREO spacecraft observing an erupting sun.

An artist's concept of STEREO surrounding the sun. Credit: NASA "With data like these, we can fly around the sun to see what's happening over the horizon—without ever leaving our desks," says STEREO program scientist Lika Guhathakurta at NASA headquarters. "I expect great advances in theoretical solar physics and space weather forecasting."

Consider the following: In the past, an active sunspot could emerge on the far side of the sun completely hidden from Earth. Then, the sun's rotation could turn that region toward our planet, spitting flares and clouds of plasma, with little warning.

"Not anymore," says Bill Murtagh, a senior forecaster at NOAA's Space Weather Prediction Center in Boulder, Colorado. "Farside active regions can no longer take us by surprise. Thanks to STEREO, we know they're coming."

NOAA is already using 3D STEREO models of CMEs (billion-ton clouds of plasma ejected by the sun) to improve space weather forecasts for airlines, power companies, satellite operators, and other customers. The full sun view should improve those forecasts even more.


 
bserving solar storms from two points of view has allowed forecasters to made 3D models of advancing coronal mass ejections (CMEs), improving predictions of Earth impacts. Credit: NOAA/SWPC


The forecasting benefits aren't limited to Earth.

"With this nice global model, we can now track solar storms heading toward other planets, too," points out Guhathakurta. "This is important for NASA missions to Mercury, Mars, asteroids … you name it."

Artist rendering of STEREO spacecraft.

An artist's concept of STEREO spacecraft. Credit: NASA NASA has been building toward this moment since Oct. 2006 when the STEREO probes left Earth, split up, and headed for positions on opposite sides of the sun (movie). Feb. 6, 2011, was the date of "opposition"—i.e., when STEREO-A and -B were 180 degrees apart, each looking down on a different hemisphere. NASA's Earth-orbiting Solar Dynamics Observatory is also monitoring the sun 24/7. Working together, the STEREO-SDO fleet should be able to image the entire globe for the next 8 years.

The new view could reveal connections previously overlooked. For instance, researchers have long suspected that solar activity can "go global," with eruptions on opposite sides of the sun triggering and feeding off of one another. Now they can actually study the phenomenon. The Great Eruption of August 2010 engulfed about 2/3rd of the stellar surface with dozens of mutually interacting flares, shock waves, and reverberating filaments. Much of the action was hidden from Earth, but plainly visible to the STEREO-SDO fleet.

"There are many fundamental puzzles underlying solar activity," says Vourlidas. "By monitoring the whole sun, we can find missing pieces."

Researchers say these first-look whole sun images are just a hint of what's to come. Movies with even higher resolution and more action will be released in the days and weeks ahead as more data are processed. Stay tuned!



Related Links:
For more information about STEREO, please visit › www.nasa.gov/stereo.

NASA Astronaut Mark Kelly Resumes Training For STS-134 Mission

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HOUSTON -- NASA astronaut Mark Kelly will resume training as commander of the STS-134 space shuttle mission on Monday, Feb. 7. With the exception of some proficiency training, Kelly has been on personal leave since Jan. 8 to care for his wife, congresswoman Gabrielle Giffords, who was critically wounded in a Tucson, Ariz. shooting.

"I am looking forward to rejoining my STS-134 crew members and finishing our training for the mission," Kelly said. "We have been preparing for more than 18 months, and we will be ready to deliver the Alpha Magnetic Spectrometer (AMS) to the International Space Station and complete the other objectives of the flight. I appreciate the confidence that my NASA management has in me and the rest of my space shuttle crew."

"We are glad to have Mark back," said Peggy Whitson, chief of the Astronaut Office at NASA's Johnson Space Center in Houston. "He is a veteran shuttle commander and knows well the demands of the job. We are confident in his ability to successfully lead this mission, and I know I speak for all of NASA in saying 'welcome back'.

A news briefing will be held at 2 p.m. CST today at Johnson to discuss Kelly's return. The briefing will be broadcast on NASA Television.

Questions will be taken from reporters at Johnson, NASA Headquarters and the Kennedy Space Center in Florida.

Participants will include:
-- Mark Kelly, commander, STS-134
-- Peggy Whitson, chief, Astronaut Office
-- Brent Jett, chief, Flight Crew Operations Directorate

Because of winter weather conditions, Johnson will be closed until noon. However, the Johnson newsroom at 281-483-5111 is staffed to receive calls from journalists requesting credentials.

On Monday, Feb. 7, NASA TV will broadcast video b-roll of Kelly's first training session with his crew at 11:30 a.m. CST. Additional b-roll of his first day of training will air at 3 p.m. The training sessions will not be available for filming by news media.
Astronaut Rick Sturckow, the backup commander for the mission, will resume his role as the deputy chief of the Astronaut Office. For more information about the STS-134 mission and crew, visit:

http://www.nasa.gov/shuttle

The Jets of Enceladus

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On Jan. 31, 2011, NASA's Cassini spacecraft passed by several of Saturn's intriguing moons, snapping images along the way. Cassini passed within about 37,282 miles of Enceladus and 17,398 miles of Helene. It also caught a glimpse of Mimas in front of Saturn's rings. In this image, Cassini snapped a picture of the famous jets erupting from the south polar terrain of Enceladus.

Image Credit: NASA/JPL/SSI

Hydraulic Systems Testing Today

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Technicians at NASA Kennedy Space Center's Launch Pad 39A will perform a final test on space shuttle Discovery's hydraulic system today.

At NASA's Johnson Space Center in Houston, Discovery's astronauts will review computer network manuals and robotic procedures today.

Space Shuttle Mission: STS-133

 Space shuttle Discovery rolls to Launch Pad 39A. 

 

Image above: Bathed in bright xenon lights, space shuttle Discovery makes its nighttime trek, known as "rollout," from the Vehicle Assembly Building to Launch Pad 39A at NASA's Kennedy Space Center in Florida. Photo credit: NASA/Kim Shiflett


During space shuttle Discovery's final spaceflight, the STS-133 crew members will take important spare parts to the International Space Station along with the Express Logistics Carrier-4.

Steve Bowen replaced Tim Kopra as Mission Specialist 2 following a bicycle injury on Jan. 15 that prohibited Kopra from supporting the launch window. Bowen last flew on Atlantis in May 2010 as part of the STS-132 crew. Flying on the STS-133 mission will make Bowen the first astronaut ever to fly on consecutive missions.

STS-134 Update:
Astronaut Rick Sturckow will serve as a backup commander for the STS-134 space shuttle mission to facilitate continued training for the crew and support teams during STS-134 Commander Mark Kelly's absence. Kelly's wife, Congresswoman Gabrielle Giffords, was critically wounded in a shooting on Jan. 8 in Tucson, Ariz. Kelly remains commander of the mission, which is targeted for launch on April 19 from NASA's Kennedy Space Center in Florida.

STS-135 Update:
The Space Shuttle Program baselined the STS-135 mission for a target launch date of June 28 at 3:48 p.m. EDT. It is NASA’s intent to fly the mission with orbiter Atlantis carrying the Raffaello multipurpose logistics module to deliver supplies, logistics and spare parts to the International Space Station. The mission also will fly a system to investigate the potential for robotically refueling existing spacecraft and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems.

In late December, the agency’s Space Operations Mission Directorate requested the shuttle and International Space Station programs take the necessary steps to maintain the capability to fly Atlantis on the STS-135 mission. The Authorization Act of 2010 directs NASA to conduct the mission, and baselining the flight enables the program to begin preparations for the mission with a target launch date of June 28. The mission would be the 135th and final space shuttle flight.

SDO Catches a Double Play

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The Solar Dynamics Observatory (SDO) caught the action when the Sun popped off two events at once on Jan. 28, 2011. A filament on the left side became unstable and erupted, while an M-1 flare (mid-sized) and a Coronal Mass Ejection on the right blasted into space. The movie, taken Jan. 26-28, 2011, shows several other flashes and bursts from the active region on the right as well.

Surprise Hidden in Titan's Smog: Cirrus-Like Clouds

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Saturn and Titan 

Titan, the largest of Saturn's moons, is about to slip behind the planet in this portrait captured by the Cassini spacecraft in 2008. Credit: NASA's Jet Propulsion Laboratory
Titan seen behind Saturn's rings 

The blurring effects of Titan's aerosol are obvious in this image, where the orange moon peeks from behind two of Saturn's rings. Small, battered Epimetheus, another of Saturn's 62 moons, appears just above the rings. Credit: NASA/JPL/Space Science Institute


Titan 
 
Titan's northern half, where it's early spring, appears slightly darker than the southern half, where it's early fall, in this image taken on March 22, 2010. Like Earth, Titan has four distinct seasons, each of which lasts about seven of Earth's years. Credit: NASA/JPL/Space Science Institute
Every day is a bad-air day on Saturn's largest moon, Titan. Blanketed by haze far worse than any smog belched out in Los Angeles, Beijing or even Sherlock Holmes's London, the moon looks like a dirty orange ball. Described once as crude oil without the sulfur, the haze is made of tiny droplets of hydrocarbons with other, more noxious chemicals mixed in. Gunk.

Icky as it may sound, Titan is really the rarest of gems: the only moon in our solar system with an atmosphere worthy of a planet. This atmosphere comes complete with lightning, drizzle and occasionally a big, summer-downpour style of cloud made of methane or ethane -- hydrocarbons that are best known for their role in natural gas.

Now, thin, wispy clouds of ice particles, similar to Earth's cirrus clouds, are being reported by Carrie Anderson and Robert Samuelson at NASA's Goddard Space Flight Center in Greenbelt, Md. The findings, published February 1 in Icarus, were made using the Composite Infrared Spectrometer (CIRS) on NASA's Cassini spacecraft.

Unlike Titan's brownish haze, the ice clouds have the pearly white appearance of freshly fallen snow. Their existence is the latest clue to the workings of Titan's intriguing atmosphere and its one-way "cycle" that delivers hydrocarbons and other organic compounds to the ground as precipitation. Those compounds don't evaporate to replenish the atmosphere, but somehow the supply has not run out (yet?).

"This is the first time we have been able to get details about these clouds," says Samuelson, an emeritus scientist at Goddard and the co-author of the paper. "Previously, we had a lot of information about the gases in Titan's atmosphere but not much about the [high-altitude] clouds."

Puffy methane and ethane clouds had been found before by ground-based observers and in images taken by Cassini's imaging science subsystem and visual and infrared mapping spectrometer. Compared to those clouds, these are much thinner and located higher in the atmosphere. "They are very tenuous and very easy to miss," says Anderson, the paper's lead author. "The only earlier hints that they existed were faint glimpses that NASA's Voyager 1 spacecraft caught as it flew by Titan in 1980."

Out on a Limb

Even before Voyager 1 reached Titan, scientists knew the moon was wrapped in a thick atmosphere that probably contained hydrocarbons. Part of that atmosphere, Voyager found, is a haze so smothering that it hides every bit of the moon's surface.

Only a small amount of visible light penetrates this haze, or aerosol, so studies rely on instruments that operate at wavelengths beyond human sight. This is how Voyager learned that Titan's atmosphere is made mostly of nitrogen, as is Earth's. Unlike Earth's atmosphere, though, Titan's has neither oxygen nor water to speak of. Instead, it contains small amounts of organic materials, including members of the hydrocarbon family such as methane, ethane and propane.

Voyager also picked up indications that Titan's stratosphere, the second-lowest layer of its atmosphere, harbored "ices made from some exotic organic compounds," Samuelson says. "At the time, that was about all we could tell."

Fast-forward a quarter-century to mid-2006, past decades of research conducted from telescopes, past Cassini's arrival at Saturn, past the European Space Agency's Huygens probe landing on Titan and taking the first pictures of the surface, past the discovery of the methane and ethane clouds. At this point, Cassini continues to orbit Saturn and visit Titan and other moons periodically.

More than a half-dozen hydrocarbons have been identified in gas form in Titan's atmosphere, but many more probably lurk there. Researchers worldwide are looking for them, including Anderson and Samuelson, who are using the CIRS (pronounced "sears") instrument on Cassini.

Pinpointing the altitudes where such gases turn into ices is painstaking work. The researchers scan up and down the atmosphere, pausing at each altitude to catalog a slew of signals that have to be teased apart later so that the molecules can be identified. "You can learn a lot about a compound, even if you have no idea what it is, by looking at how it is distributed vertically," says Anderson. "Where does it accumulate? Where does it dissipate? How thick is the boundary? Is there layering going on?"

Anderson and Samuelson start a series of observations near Titan's north pole, at roughly the same latitudes Voyager looked at, 62 °N and 70 °N. On Earth, these would fall just inside and outside the ring for the Arctic Circle.

The team focuses on the observations made when CIRS is positioned to peer into the atmosphere at an angle, grazing the edge of Titan. This path through the atmosphere is longer than the one when the spacecraft looks straight down at the surface. Planetary scientists call this "viewing on the limb," and it raises the odds of encountering enough molecules of interest to yield a strong signal.

It works. When the researchers comb through their data, they succeed in separating the telltale signatures of ice clouds from the aerosol. "These beautiful, beautiful ice clouds are optically thin, and they're diffuse," says Anderson. "But we were able to pick up on them because of the long path lengths of the observations."

In addition to spotting the clouds, the researchers gather enough information to measure the sizes of the ice particles. The results get reported in a January 2010 Icarus paper by Anderson, Samuelson, their Goddard colleague Gordon Bjoraker and Richard Achterberg, a University of Maryland staff member working at Goddard.

"That was convincing evidence," Anderson says. "What Voyager had seen was real."

That Sinking Feeling

Clouds on Titan can't be made from water because of the planet's extreme cold. "If Titan has any water on the surface, it would be solid as a rock," says Goddard's Michael Flasar, the Principal Investigator for CIRS.

Instead, the key player is methane. The action starts high in the atmosphere, where some of the methane gets broken up and reforms into ethane and other hydrocarbons, or combines with nitrogen to make materials called nitriles. Any of these compounds can probably form clouds if enough accumulates in a sufficiently cold area.

The cloud-forming temperatures occur in the "cold, cold depths of Titan's stratosphere," says Anderson. Researchers think that the compounds get moved downward by a constant stream of gas flowing from the pole in the warmer hemisphere to the pole in the colder hemisphere. There, the gas sinks.

This circulation pattern steals so much gas from the warmer hemisphere that researchers can measure the imbalance. The influx of all this gas gives the colder hemisphere more clouds. "At colder temperatures, more gas will condense anyway," Anderson explains, "and on top of that, the atmosphere dumps a whole bunch of extra gas there."

She and Samuelson think this is why the ice clouds were first spotted in the north. When Voyager flew by in November 1980, the north had just crossed from winter into spring. And the north was in mid-winter when the team conducted their early observations. (One Titan year lasts 29-1/2 Earth years, so spring came again to Titan's north in August 2009.)

Still, the team figured, the south shouldn't lack ice clouds; it should just have fewer of them. "For 30 years, Bob [Samuelson] had been saying that these clouds should exist in the southern hemisphere," says Anderson, "so we decided to look."

The team checked Titan's southern hemisphere (at 58 °S latitude) and both sides of the equator (15 °N and 15 °S). Sure enough, they spotted clouds in all three locations. And as predicted, the clouds in the north were more plentiful -- in fact, three times more plentiful -- than those just south of the equator.

"The fact that the clouds are more enhanced at the cold polar region is a promising sign," says Flasar. "It strengthens this idea that the molecules making up these clouds are being carried downward by this global circulation."

Exotic Ices

Part of Titan's allure has long been the organic compounds in the atmosphere, especially because some are thought to be involved in the events that led to life on Earth. One of those is cyanoacetylene, a member of the nitrile family. The compound's distinctive signature made it the first to be picked up in the northern ice clouds by Voyager 1 and by Anderson and Samuelson.

To make a connection between these molecules and life isn't the point for Anderson, though. "I just love ices and aerosols," she says, "and Titan is this great natural laboratory for studying them."

As the researchers continue to identify compounds in Titan's atmosphere, the next likely candidate for an ice is hydrogen cyanide, a nitrile with an earthly reputation as a poison. In the aerosol, the team is investigating an intriguing feature in the data that seems to represent larger hydrocarbons than anybody has identified before, according to Samuelson. Early clues suggest the signature could indicate polycyclic aromatic hydrocarbons (PAHs), which typically get noticed on Earth as pollutants released by the burning of fossil fuels. In space, PAHs form in the regions where stars are born and die.

Each nugget of information like this is helping scientists piece together the life cycle and ultimate fate of Titan's hydrocarbons, which never reenter the atmosphere via evaporation. "They fall to the surface, and it's a dead end," says Samuelson, "and yet Titan's atmosphere still has methane in it. We are trying to find out why."

The Great Switcheroo

At first, Titan's frozen nitriles seem entirely unrelated to Earth clouds. Even putting aside their exotic ingredients, they form much higher in the atmosphere: at altitudes of about 30 to 60 miles (in the stratosphere) versus no more than 11 miles (in the troposphere) for nearly all Earth clouds.

But Earth does have a few polar stratospheric clouds that appear over Antarctica (and sometimes in the Arctic) during winter. These clouds form in the exceptionally cold air that gets trapped in the center of the polar vortex, a fierce wind that whips around the pole high in the stratosphere. This is the same region where Earth's ozone hole is found.

Titan has its own polar vortex and may even have a counterpart to our ozone hole. The degree of similarity is intriguing, says Flasar, given the different compositions and chemistries of the stratospheric clouds on Earth versus Titan.

"We are starting to find out how similar Titan's clouds are to Earth's," says Samuelson. "How do they compare? How do they not compare?"

The big test of scientists' understanding of Titan's atmosphere will come in 2017, when summer comes to the north and the south plunges into winter. "We expect to find a complete reversal in the circulation of gas then," says Anderson. "The gas should start to flow from the north to the south. And that should mean most of the high-altitude ice clouds will be in the southern hemisphere."

Other major changes are in store for Titan then, Flasar adds, including the disappearance of the fierce winds around the north pole. "The big question is: will the vortex go out with a bang or whimper?" he says. "On Earth, it goes out with a bang. It's very dramatic. But on Titan, maybe the vortex just gradually fizzles out like the smile of the Chesire cat."

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency, and the Italian Space Agency. NASA's Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The CIRS team is based at NASA's Goddard Space Flight Center in Greenbelt, Md., where the instrument was built.

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