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.


 
 

 

Headlines October 29, 2014

News: Unmanned rocket explodes just six seconds after taking off - A NASA rocket due to be visible across the East Coast on its way to the International Space Station has blown up on the Launchpad. IG: Former chief of wounded warrior office broke law, DOD regs - The Defense Department inspector general has recommended “corrective action”...
 
 

News Briefs October 29, 2014

F-35C makes first landing at Virginia Beach Navy base The Navy says an operational F-35C joint strike fighter has landed at Naval Air Station Oceana for the first time. Naval Air Station Oceana is the Navy’s master jet base on the East Coast. The Navy says the plane came to the Virginia Beach base Oct....
 
 

Time to turn to American technology for space launch

For the first time since the Cold War, the United States has deployed armored reinforcements to Europe. To counter Russia’s aggression, several hundred troops and 20 tanks are now in the Baltic. Yet the U.S. military is still injecting millions into the Russian military industrial complex. In late August, the United Launch Alliance – the...
 

 
Air Force photograph by Joe Davila

Boeing, Air Force demonstrate Minuteman III readiness in flight test

Air Force photograph by Joe Davila Boeing supported the launch of an unarmed Minuteman III intercontinental ballistic missile at Vandenberg Air Force Base, Calif., on Sept. 23, 2014. Boeing supported the U.S. Air Force’s succ...
 
 

Pentagon going to court for refusing to release Sikorsky data

PETALUMA, Calif. – The Pentagon is refusing to release any data on any prime contractors participating in the 25-year-old Comprehensive Subcontracting Plan Test Program. The American Small Business League launched a program in 2010 to expose the fraud and abuse against small businesses the CSPTP had allowed. As a test the ASBL requested the most...
 
 
Northrop Grumman photograph

Raytheon Griffin C flight tests demonstrate in-flight retargeting capability

Northrop Grumman photograph Northrop Grumman has received a contract from the U.S. Marine Corps for low-rate initial production of the AN/TPS-80 Ground/Air Task Oriented Radar (G/ATOR). G/ATOR is the first ground-based multi-mi...
 




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>