NASA Research Shows DNA Building Blocks Can Be Made in Space

Dwayne Brown

Headquarters, Washington                                        

 

Nancy Neal-Jones

Goddard Space Flight Center, Greenbelt, Md.

WASHINGTON -- NASA-funded researchers have found more evidence meteorites can carry DNA components created in space.

Scientists have detected the building blocks of DNA in meteorites since the 1960s, but were unsure whether they were created in space or resulted from contamination by terrestrial life. The latest research indicates certain nucleobases -- the building blocks of our genetic material -- reach the Earth on meteorites in greater diversity and quantity than previously thought.

The discovery adds to a growing body of evidence that the chemistry inside asteroids and comets is capable of making building blocks of essential biological molecules. Previously, scientists found amino acids in samples of comet Wild 2 from NASA’s Stardust mission and in various carbon-rich meteorites. Amino acids are used to make proteins, the workhorse molecules of life. Proteins are used in everything from structures such as hair to enzymes, which are the catalysts that speed up or regulate chemical reactions.

The findings will be published in the online edition of the Proceedings of the National Academy of Sciences. In the new work, scientists analyzed samples of 12 carbon-rich meteorites, nine of which were recovered from Antarctica. The team found adenine and guanine, which are components of DNA nucleobases.

Also, in two of the meteorites, the team discovered for the first time trace amounts of three molecules related to nucleobases that almost never are used in biology. These nucleobase-related molecules, called nucleobase analogs, provide the first evidence that the compounds in the meteorites came from space and not terrestrial contamination.

"You would not expect to see these nucleobase analogs if contamination from terrestrial life was the source, because they're not used in biology," said Michael Callahan, astrobiologist and lead author of the paper from NASA's Goddard Space Flight Center in Greenbelt, Md. "However, if asteroids are behaving like chemical 'factories' cranking out prebiotic material, you would expect them to produce many variants of nucleobases, not just the biological ones, because of the wide variety of ingredients and conditions in each asteroid."

Additional evidence came from research to further rule out the possibility of terrestrial contamination as a source of these molecules. The team analyzed an eight-kilogram (17.6-pound) sample of ice from Antarctica, where most of the meteorites in the study were found. The amounts of nucleobases found in the ice were much lower than in the meteorites. More significantly, none of the nucleobase analogs were detected in the ice sample. The team also analyzed a soil sample collected near one of the non-Antarctic meteorite’s fall site. As with the ice sample, the soil sample had none of the nucleobase analog molecules present in the meteorite.

Launched in Feb. 7, 1999, Stardust flew past an asteroid and traveled halfway to Jupiter to collect particle samples from the comet Wild 2. The spacecraft returned to Earth's vicinity to drop off a sample-return capsule on January 15, 2006.

The research was funded by NASA’s Astrobiology Institute at the agency’s Ames Research Laboratory in Moffett Field Calif., and the Goddard Center for Astrobiology in Greenbelt, Md.; the NASA Astrobiology Exobiology and Evolutionary Biology Program and the NASA Postdoctoral Program at the agency's Headquarters in Washington.

Additional information and images are available at http://www.nasa.gov/topics/solarsystem/features/dna-meteorites.html.

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NASA Stardust Spacecraft Officially Ends Operations

Dwayne Brown

Headquarters, Washington

DC Agle

Jet Propulsion Laboratory, Pasadena, Calif.

PASADENA, Calif. -- NASA's Stardust spacecraft sent its last transmission to Earth at 7:33 p.m. EDT Thursday, March 24, shortly after depleting fuel and ceasing operations. During an 11-year period, the venerable spacecraft collected and returned comet material to Earth and was reused after the end of its prime mission in 2006 to observe and study another comet during February 2011.

The Stardust team performed the burn to depletion, because the comet hunter was literally running on fumes. The depletion maneuver command was sent from the Stardust-NExT mission control area at Lockheed Martin Space Systems in Denver. The operation was designed to fire Stardust's rockets until no fuel remained in the tank or fuel lines. The spacecraft sent acknowledgment of its last command from approximately 194 million miles away in space.

"This is the end of the spacecraft's operations, but really just the beginnings of what this spacecraft's accomplishments will give to planetary science," said Lindley Johnson, Stardust-NExT and Discovery program executive at NASA Headquarters in Washington. "The treasure-trove of science data and engineering information collected and returned by Stardust is invaluable for planning future deep space planetary missions."

After completion of the burn, mission personnel began comparing the computed amount of fuel consumed during the engine firing with the anticipated amount based on consumption models. The models are required to track fuel levels, because there are no fully reliable fuel gauges for spacecraft in the weightless environment of space. Mission planners use approximate fuel usage by reviewing the history of the vehicle's flight, how many times and how long its rocket motors fired.

"Stardust's motors burned for 146 seconds," said Allan Cheuvront, Lockheed Martin Space Systems Company program manager for Stardust-NExT in Denver. "We'll crunch the numbers and see how close the reality matches up with our projections. That will be a great data set to have in our back pocket when we plan for future missions."

Launched Feb. 7, 1999, Stardust flew past the asteroid named Annefrank and traveled halfway to Jupiter to collect the particle samples from the comet Wild 2. The spacecraft returned to Earth's vicinity to drop off a sample return capsule eagerly awaited by comet scientists.

NASA re-tasked the spacecraft as Stardust-NExT to perform a bonus mission and fly past comet Tempel 1, which was struck by the Deep Impact mission in 2005. The mission collected images and other scientific data to compare with images of that comet collected by the Deep Impact mission in 2005. Stardust traveled approximately 13 million miles around the sun in the weeks after the successful Tempel 1 flyby. The Stardust-NExT mission met all mission goals, and the spacecraft was extremely successful during both missions. From launch until final rocket engine burn, Stardust travelled approximately 3.54 billion miles.

After the mileage logged in space, the Stardust team knew the end was near for the spacecraft. With its fuel tank empty and final radio transmission concluded, history's most traveled comet hunter will move from NASA's active mission roster to retired.

"This kind of feels like the end of one of those old western movies where you watch the hero ride his horse towards the distant setting sun -- and then the credits begin to roll," said Stardust-NExT project manager Tim Larson from NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Only there's no setting sun in space."

Stardust and Stardust-NExT missions were managed by JPL for NASA's Science Mission Directorate in Washington. The missions were part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Joe Veverka of Cornell University was the Stardust-NExT principal investigator. Don Brownlee of the University of Washington in Seattle was the Stardust principal investigator. Lockheed Martin Space Systems built the spacecraft and managed day-to-day mission operations.

For more information about Stardust and Stardust-NExT, visit http://stardustnext.jpl.nasa.gov.

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NASA Releases Images of Man-Made Crater on Comet

Dwayne Brown

Headquarters, Washington

 

DC Agle

Jet Propulsion Laboratory, Pasadena, Calif.

 

Blaine Friedlander

Cornell University, Ithaca, N.Y.

 

PASADENA, Calif. -- NASA's Stardust spacecraft returned new images of a comet showing a scar resulting from the 2005 Deep Impact mission. The images also showed the comet has a fragile and weak nucleus.

The spacecraft made its closest approach to comet Tempel 1 on Monday, Feb. 14, at 8:40 p.m. PST at a distance of approximately 111 miles. Stardust took 72 high-resolution images of the comet. It also accumulated 468 kilobytes of data about the dust in its coma, the cloud that is a comet's atmosphere. The craft is on its second mission of exploration called Stardust-NExT, having completed its prime mission collecting cometary particles and returning them to Earth in 2006.

The Stardust-NExT mission met its goals which included observing surface features that changed in areas previously seen during the 2005 Deep Impact mission; imaging new terrain; and viewing the crater generated when the 2005 mission propelled an impactor at the comet.

"This mission is 100 percent successful," said Joe Veverka, Stardust-NExT principal investigator of Cornell University, Ithaca, N.Y. "We saw a lot of new things that we didn't expect, and we'll be working hard to figure out what Tempel 1 is trying to tell us."

Several of the images provide tantalizing clues to the result of the Deep Impact mission's collision with Tempel 1.

"We see a crater with a small mound in the center, and it appears that some of the ejecta went up and came right back down," said Pete Schultz of Brown University, Providence, R.I. "This tells us this cometary nucleus is fragile and weak based on how subdued the crater is we see today."

Engineering telemetry downlinked after closest approach indicates the spacecraft flew through waves of disintegrating cometary particles including a dozen impacts that penetrated more than one layer of its protective shielding.

"The data indicate Stardust went through something similar to a B-17 bomber flying through flak in World War II," said Don Brownlee, Stardust-NExT co-investigator from the University of Washington in Seattle. "Instead of having a little stream of uniform particles coming out, they apparently came out in chunks and crumbled."

While the Valentine's Day night encounter of Tempel 1 is complete, the spacecraft will continue to look at its latest cometary obsession from afar.                                              

"This spacecraft has logged over 3.5 billion miles since launch, and while its last close encounter is complete, its mission of discovery is not," said Tim Larson, Stardust-NExT project manager at JPL. "We'll continue imaging the comet as long as the science team can gain useful information, and then Stardust will get its well-deserved rest."

Stardust-NExT is a low-cost mission that is expanding the investigation of comet Tempel 1 initiated by the Deep Impact spacecraft. The mission is managed by JPL for NASA's Science Mission Directorate in Washington. Lockheed Martin Space Systems in Denver built the spacecraft and manages day-to-day mission operations.

For more information about Stardust-NExT, visit http://stardustnext.jpl.nasa.gov.

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NASA Reschedules News Conference on Stardust-Next Comet Flyby

Dwayne Brown

Headquarters, Washington                                   

 

DC Agle            

Jet Propulsion Laboratory, Pasadena, Calif.

 

Blaine Friedlander

Cornell University, Ithaca, N.Y.

PASADENA, Calif. -- NASA has rescheduled the news conference about the Stardust-NExT comet flyby for 12:30 p.m. PST (3:30 p.m. EST) today. The briefing will release images and early data from the comet encounter and will be carried live on NASA Television and the agency's website.

The participants are:

-Ed Weiler, NASA's associate administrator, Science Mission Directorate, Washington

-Joe Veverka, Stardust-NExT principal investigator, Cornell University

-Tim Larson, Stardust-NExT project manager, NASA's Jet Propulsion Laboratory, Pasadena, Calif.

-Don Brownlee, Stardust-NExT co-investigator, University of Washington, Seattle

-Pete Schultz, Stardust-NExT co-investigator, Brown University

The news conference was originally scheduled for 10 a.m. PST (1 p.m. EST). The additional time will allow scientists to process and analyze data and images gathered when the spacecraft flew past comet Tempel 1, with closest approach at a distance of 112 miles. The mission team had expected the closest-approach images to be sent first. Instead, the images were downlinked in chronological order, starting with the most distant approach views.

The briefing also can be viewed on one of JPL's Ustream channels at http://www.ustream.tv/user/NASAJPL2.

The first six, most distant approach images are available online at http://www.nasa.gov/stardust and http://www.jpl.nasa.gov.

For NASA TV streaming video, scheduling and downlink information, visit http://www.nasa.gov/ntv.

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This article was sponsored by Forensic Science Books.

NASA Hosting Events For Valentine's Night Comet Encounter

Dwayne Brown

Headquarters, Washington     

 

DC Agle               

Jet Propulsion Laboratory, Pasadena, Calif.

 

Blaine Friedlander

Cornell University, Ithaca, N.Y.

 

PASADENA, Calif. -- NASA will host several live media activities for the Stardust-NExT mission's close encounter with comet Tempel 1. The closest approach is expected at approximately 8:37 p.m. PST, with confirmation received on Earth at about 8:56 p.m. PST on Monday, Feb. 14.

Live coverage of the Tempel 1 encounter will begin at 8:30 p.m. Feb. 14 on NASA Television and the agency's website. The coverage will include live commentary from mission control at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., and video from Lockheed Martin Space System's mission support area in Denver.

A news briefing is planned for 10 a.m. on Feb. 15. Scheduled participants are:

-Ed Weiler, NASA's associate administrator, Science Mission Directorate

-Joe Veverka, Stardust-NExT principal investigator, Cornell University

-Tim Larson, Stardust-NExT project manager, JPL

-Don Brownlee, Stardust-NExT co-investigator, University of Washington, Seattle

To cover the Tempel 1 flyby at JPL, journalists must contact the JPL Media Relations Office at 818-354-5011. Valid media credentials are required. Non-U.S. citizens must bring passports.

Starting Feb. 14 at 8 p.m., news media representatives can watch live coverage of the control room via a feed to JPL's von Karman Auditorium. The auditorium will remain open through the evening for media. Reporters who will not travel to JPL may call the Media Relations Office to make arrangements to ask questions during the Feb. 15 briefing.

Mission coverage schedule (all times PST and subject to change):

8:30 to 10 p.m., Feb. 14: Live NASA TV commentary begins from mission control; includes coverage of closest approach and the re-establishment of contact with the spacecraft following the encounter.

Midnight to 1:30 a.m., Feb. 15: NASA TV commentary will chronicle the arrival and processing of the first five of 72 close-approach images expected to be down linked after the encounter. The images are expected to include a close-up view of the comet's surface.

10 a.m., Feb. 15: News briefing

Starting on Feb. 9, NASA TV will air Stardust-NExT mission animation and b-roll during its Video File segments. For NASA TV streaming video, scheduling and downlink information, visit http://www.nasa.gov/ntv.

Live commentary and the news conference also will be carried live on one of JPL's Ustream channels. Viewers during events can engage in a real-time chat and submit questions to the Stardust-NExT team at http://www.ustream.tv/user/NASAJPL2.

The public can watch a real-time animation of the Stardust-NExT comet flyby using NASA's new "Eyes on the Solar System" Web tool. JPL created this 3-D environment, which allows people to explore the solar system directly from their computers. It is available at http://solarsystem.nasa.gov/eyes.

This flyby of Tempel 1 will give scientists an opportunity to look for changes on the comet's surface since it was visited by NASA's Deep Impact spacecraft in July 2005. Since then, Tempel 1 has completed one orbit of the sun, and scientists are looking forward to monitoring any differences in the comet.

During its 12 years in space, Stardust became the first spacecraft to collect samples of a comet (Wild 2) in 2004, which were sent in 2006 to Earth for study. The mission is managed by JPL for NASA's Science Mission Directorate in Washington. Lockheed Martin Space Systems in Denver built the spacecraft and manages day-to-day mission operations.

A press kit and other detailed information about Stardust-NExT is available at http://stardustnext.jpl.nasa.gov.

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NASA Hosting Events For Valentine's Night Comet Encounter

Dwayne Brown

Headquarters, Washington     

 

DC Agle               

Jet Propulsion Laboratory, Pasadena, Calif.

 

Blaine Friedlander

Cornell University, Ithaca, N.Y.

 

PASADENA, Calif. -- NASA will host several live media activities for the Stardust-NExT mission's close encounter with comet Tempel 1. The closest approach is expected at approximately 8:37 p.m. PST, with confirmation received on Earth at about 8:56 p.m. PST on Monday, Feb. 14.

Live coverage of the Tempel 1 encounter will begin at 8:30 p.m. Feb. 14 on NASA Television and the agency's website. The coverage will include live commentary from mission control at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., and video from Lockheed Martin Space System's mission support area in Denver.

A news briefing is planned for 10 a.m. on Feb. 15. Scheduled participants are:

-Ed Weiler, NASA's associate administrator, Science Mission Directorate

-Joe Veverka, Stardust-NExT principal investigator, Cornell University

-Tim Larson, Stardust-NExT project manager, JPL

-Don Brownlee, Stardust-NExT co-investigator, University of Washington, Seattle

To cover the Tempel 1 flyby at JPL, journalists must contact the JPL Media Relations Office at 818-354-5011. Valid media credentials are required. Non-U.S. citizens must bring passports.

Starting Feb. 14 at 8 p.m., news media representatives can watch live coverage of the control room via a feed to JPL's von Karman Auditorium. The auditorium will remain open through the evening for media. Reporters who will not travel to JPL may call the Media Relations Office to make arrangements to ask questions during the Feb. 15 briefing.

Mission coverage schedule (all times PST and subject to change):

8:30 to 10 p.m., Feb. 14: Live NASA TV commentary begins from mission control; includes coverage of closest approach and the re-establishment of contact with the spacecraft following the encounter.

Midnight to 1:30 a.m., Feb. 15: NASA TV commentary will chronicle the arrival and processing of the first five of 72 close-approach images expected to be down linked after the encounter. The images are expected to include a close-up view of the comet's surface.

10 a.m., Feb. 15: News briefing

Starting on Feb. 9, NASA TV will air Stardust-NExT mission animation and b-roll during its Video File segments. For NASA TV streaming video, scheduling and downlink information, visit http://www.nasa.gov/ntv.

Live commentary and the news conference also will be carried live on one of JPL's Ustream channels. Viewers during events can engage in a real-time chat and submit questions to the Stardust-NExT team at http://www.ustream.tv/user/NASAJPL2.

The public can watch a real-time animation of the Stardust-NExT comet flyby using NASA's new "Eyes on the Solar System" Web tool. JPL created this 3-D environment, which allows people to explore the solar system directly from their computers. It is available at http://solarsystem.nasa.gov/eyes.

This flyby of Tempel 1 will give scientists an opportunity to look for changes on the comet's surface since it was visited by NASA's Deep Impact spacecraft in July 2005. Since then, Tempel 1 has completed one orbit of the sun, and scientists are looking forward to monitoring any differences in the comet.

During its 12 years in space, Stardust became the first spacecraft to collect samples of a comet (Wild 2) in 2004, which were sent in 2006 to Earth for study. The mission is managed by JPL for NASA's Science Mission Directorate in Washington. Lockheed Martin Space Systems in Denver built the spacecraft and manages day-to-day mission operations.

A press kit and other detailed information about Stardust-NExT is available at http://stardustnext.jpl.nasa.gov.

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Date with a Comet - Valentine's Day 2011

Stardust-NExT is a mission to reuse the Stardust spacecraft to further the exploration of comet Tempel 1.

Tempel 1 was the target of Deep Impact. Deep Impact discovered that this is a most interesting comet.

We want to see more of the surface and we also want to see what changes have occurred since Deep Impact was there five years ago. The primary purpose is to observe how the comet has changed;how the nucleus has changed, to compare to what it was like back in 2005 with the previous pass near the sun. We call them perihelion passes. We also would want to extend the mapping and the observation of the nucleus to see new areas of the nucleus that we haven’t seen before.

So that it would help complete the mapping of the nucleus of this comet. And then, if possible, we would like to be able to image the crater that was left behind. The key challenges for an extended mission like this are one, dealing with the age of the spacecraft.

The spacecraft is almost 12 years old. Very little fuel is left; we’ve used most of it already. And then the third challenge, for a comet mission, is the navigation. One of the navigation challenges with getting close to a comet is predicting its trajectory.

We know that, as they get close to the sun, comets generate a lot of activity. The jets, the outbursts, all of those change the trajectory somewhat of the comet. We have a navigation camera and we photograph where the comet is on approach, and then we take that information, turn it into trajectory corrections, to put us in the right place at the right time.

One of the challenges of designing a spacecraft to go to a comet is, how do you protect it? There’s a coma that goes out in front of the comet. And that coma contains particles that could be large.

We’re flying by at a little over ten kilometers per second. That’s somewhat on the order of 25,000 miles per hour. It doesn’t take much of a particle to cause damage.

The Stardust spacecraft is a very unique spacecraft. It was built for a comet flyby. So, it was built to fly close to a comet. And because of that, it has some very robust shields on the front of the spacecraft that will be able to stop a centimeter-sized particle traveling six kilometers per second and not damage the spacecraft.

These are exciting things. They’re all different. Every time we go near one we find something new, and the opportunity for discovery is absolutely momentous.

NASA Spacecraft Prepares For Valentine's Day Comet Rendezvous

Dwayne Brown

Headquarters, Washington     

 

DC Agle               

Jet Propulsion Laboratory, Pasadena, Calif.

WASHINGTON -- NASA's Stardust-NExT spacecraft is nearing a celestial date with comet Tempel 1 at approximately 11:37 p.m. EST, on Feb. 14. The mission will allow scientists for the first time to look for changes on a comet's surface that occurred following an orbit around the sun.

The Stardust-NExT, or New Exploration of Tempel, spacecraft will take high-resolution images during the encounter, and attempt to measure the composition, distribution, and flux of dust emitted into the coma, or material surrounding the comet's nucleus. Data from the mission will provide important new information on how Jupiter-family comets evolved and formed.

The mission will expand the investigation of the comet initiated by NASA's Deep Impact mission. In July 2005, the Deep Impact spacecraft delivered an impactor to the comet's surface to study its composition. The Stardust spacecraft may capture an image of the crater created by the impactor. This would be an added bonus to the huge amount of data that mission scientists expect to obtain.

"Every day we are getting closer and closer and more and more excited about answering some fundamental questions about comets," said Joe Veverka, Stardust-NExT principal investigator at Cornell University. "Going back for another look at Tempel 1 will provide new insights on how comets work and how they were put together four-and-a-half billion years ago."

At approximately 209 million miles away from Earth, Stardust-NExT will be almost on the exact opposite side of the solar system at the time of the encounter. During the flyby, the spacecraft will take 72 images and store them in an on board computer.

Initial raw images from the flyby will be sent to Earth for processing that will begin at approximately 3 a.m. EST on Feb. 15. Images are expected to be available at approximately 4:30 a.m. EST.

As of today, the spacecraft is approximately 15.3 million miles away from its encounter. Since 2007, Stardust-NExT executed eight flight path correction maneuvers, logged four circuits around the sun and used one Earth gravity assist to meet up with Tempel 1.

Another three maneuvers are planned to refine the spacecraft's path to the comet. Tempel 1's orbit takes it as close in to the sun as the orbit of Mars and almost as far away as the orbit of Jupiter. The spacecraft is expected to fly past the 3.7 mile-wide comet at a distance of approximately 124 miles.

In 2004, the Stardust mission became the first to collect particles directly from comet Wild 2, as well as interstellar dust. Samples were returned in 2006 for study via a capsule that detached from the spacecraft and parachuted to the ground southwest of Salt Lake City.

Mission controllers placed the still viable Stardust spacecraft on a trajectory that could potentially reuse the flight system if a target of opportunity presented itself. In January 2007, NASA re-christened the mission Stardust-NExT and began a four-and-a-half year journey to comet Tempel 1.

"You could say our spacecraft is a seasoned veteran of cometary campaigns," said Tim Larson, project manager for Stardust-NExT at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif. "It's been half-way to Jupiter, executed picture-perfect flybys of an asteroid and a comet, collected cometary material for return to Earth, then headed back out into the void again, where we asked it to go head-to-head with a second comet nucleus."

The mission team expects this flyby to write the final chapter of the spacecraft's success-filled story. The spacecraft is nearly out of fuel as it approaches 12 years of space travel, logging almost 3.7 billion miles since launch in 1999. This flyby and planned post-encounter imaging are expected to consume the remaining fuel.

JPL manages mission for the agency's Science Mission Directorate in Washington. Lockheed Martin Space Systems in Denver built the spacecraft and manages day-to-day mission operations.

For more information about the Stardust-NExt mission, visit http://stardustnext.jpl.nasa.gov/.

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