Space

November 5, 2012

NASA’s Curiosity rover provides clues to changes In Martian atmosphere

NASA’s car-sized rover, Curiosity, has taken significant steps toward understanding how Mars may have lost much of its original atmosphere.

Learning what happened to the Martian atmosphere will help scientists assess whether the planet ever was habitable. The present atmosphere of Mars is 100 times thinner than Earth’s.

A set of instruments aboard the rover has ingested and analyzed samples of the atmosphere collected near the “Rocknest” site in Gale Crater where the rover is stopped for research. Findings from the Sample Analysis at Mars (SAM) instruments suggest that loss of a fraction of the atmosphere, resulting from a physical process favoring retention of heavier isotopes of certain elements, has been a significant factor in the evolution of the planet. Isotopes are variants of the same element with different atomic weights.

Initial SAM results show an increase of 5 percent in heavier isotopes of carbon in the atmospheric carbon dioxide compared to estimates of the isotopic ratios present when Mars formed. These enriched ratios of heavier isotopes to lighter ones suggest the top of the atmosphere may have been lost to interplanetary space. Losses at the top of the atmosphere would deplete lighter isotopes. Isotopes of argon also show enrichment of the heavy isotope, matching previous estimates of atmosphere composition derived from studies of Martian meteorites on Earth.

Scientists theorize that in Mars’ distant past its environment may have been quite different, with persistent water and a thicker atmosphere. NASA’s Mars Atmosphere and Volatile Evolution, or MAVEN, mission will investigate possible losses from the upper atmosphere when it arrives at Mars in 2014.

With these initial sniffs of Martian atmosphere, SAM also made the most sensitive measurements ever to search for methane gas on Mars. Preliminary results reveal little to no methane. Methane is of interest as a simple precursor chemical for life. On Earth, it can be produced by either biological or non-biological processes.

Methane has been difficult to detect from Earth or the current generation of Mars orbiters because the gas exists on Mars only in traces, if at all. The Tunable Laser Spectrometer (TLS) in SAM provides the first search conducted within the Martian atmosphere for this molecule. The initial SAM measurements place an upper limit of just a few parts methane per billion parts of Martian atmosphere, by volume, with enough uncertainty that the amount could be zero.

“Methane is clearly not an abundant gas at the Gale Crater site, if it is there at all. At this point in the mission we’re just excited to be searching for it,” said SAM TLS lead Chris Webster of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif. “While we determine upper limits on low values, atmospheric variability in the Martian atmosphere could yet hold surprises for us.”

In Curiosity’s first three months on Mars, SAM has analyzed atmosphere samples with two laboratory methods. One is a mass spectrometer investigating the full range of atmospheric gases. The other, TLS, has focused on carbon dioxide and methane.
During its two-year prime mission, the rover also will use an instrument called a gas chromatograph that separates and identifies gases. The instrument also will analyze samples of soil and rock, as well as more atmosphere samples.

“With these first atmospheric measurements we already can see the power of having a complex chemical laboratory like SAM on the surface of Mars,” said SAM Principal Investigator Paul Mahaffy of NASA’s Goddard Space Flight Center in Greenbelt, Md. “Both atmospheric and solid sample analyses are crucial for understanding Mars’ habitability.”

SAM is set to analyze its first solid sample in the coming weeks, beginning the search for organic compounds in the rocks and soils of Gale Crater. Analyzing water-bearing minerals and searching for and analyzing carbonates are high priorities for upcoming SAM solid sample analyses.

Researchers are using Curiosity’s 10 instruments to investigate whether areas in Gale Crater ever offered environmental conditions favorable for microbial life. JPL manages the project for NASA’s Science Mission Directorate in Washington. The SAM Instrument was developed at Goddard with instrument contributions from Goddard, JPL and the University of Paris in France.




All of this week's top headlines to your email every Friday.


 
 

 
lm-orion3

Orion spacecraft transfers To launch abort system facility

https://www.youtube.com/watch?v=j68mszdhTmY NASA and Lockheed Martin have finished fueling the Orion spacecraft with ammonia, hydrazine and high pressure helium at Kennedy Space Center’s Payload Hazardous Servicing Facili...
 
 

NASA telescopes find clear skies, water vapor on exoplanet

Astronomers using data from three of NASA’s space telescopes – Hubble, Spitzer and Kepler – have discovered clear skies and steamy water vapor on a gaseous planet outside our solar system. The planet is about the size of Neptune, making it the smallest planet from which molecules of any kind have been detected. “This discovery...
 
 
NASA photograph by Aubrey Gemignani

New crew launches to space station to continue scientific research

NASA photgoraph Three crew members are heading to the International Space Station after launching in a Soyuz spacecraft from the Baikonur Cosmodrome in Kazakhstan at 4:25 p.m., EDT, Sept. 25. Three crew members representing the...
 

 

NASA expands commercial space program, requests proposals for IS resupply

On the heels of awarding groundbreaking contracts to U.S. commercial space companies to ferry American astronauts to the International Space Station, NASA has released a request for proposals for the next round of contracts for private-sector companies to deliver experiments and supplies to the orbiting laboratory. Under the Commercial Resupply Services 2 RFP, NASA intends...
 
 

ATK offers solid solution to U.S. Air Force’s RD-180 replacement request

ATK has provided the U.S. Air Force an American-made commercial solid rocket solution as a replacement for the RD-180 Russian-made, first-stage engine of United Launch Alliance’s Atlas V launch vehicle. “ATK’s solid rocket propulsion solution provides a cost-effective, reliable solution based on advanced technology,” said Blake Larson, president of ATK’s Aerospace ...
 
 

SpaceX breaks ground on Texas rocket launch site

BROWNSVILLE, Texas – The commercial rocket launches that could begin as early as 2016 in the southernmost tip of Texas will be a critical step toward one day establishing a human presence on Mars, SpaceX founder and CEO Elon Musk said Sept 22. With waves from the Gulf of Mexico crashing just over the dunes...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>