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 September 3, 2015

News Carter To China: US ‘Will Fly, Sail, Operate Wherever Law Allows’ Defense Secretary Ash Carter, in a speech billed as all about a new personnel approach for the Pentagon, laid out a clear line in the sand of the temporary islands the Chinese have been building. http://breakingdefense.com/2015/09/carter-to-china-us-will-fly-sail-operate-wherever-law-allows/ LRS-B details emerge: Major t...
 
 

News Briefs September 3, 2015

Soldier injured after parachute failed to deploy A soldier was injured during a U.S. Army Special Operations parachute training exercise in western Montana. Army officials at Fort Bragg, N.C., say 16 soldiers were conducting a free-fall parachute jump from two Blackhawk helicopters near Hamilton Aug. 31 when one soldier had an equipment malfunction and was...
 
 

Boeing, Jet2.com finalize order for 27 Next Generation 737-800s

Boeing and UK Leisure Airline Jet2.com have finalized an order for 27 Next Generation 737-800s, valued at approximately $2.6 billion at current list prices. Jet2.com currently operates an all-Boeing fleet of nearly 60 aircraft; however, this is the organization’s first direct Boeing order.† The aircraft will be used to take the company’s package holiday and...
 

 
boeing-emirates

Boeing, Emirates celebrate airline’s 150th 777 delivery

Boeing and Emirates Airline Sept. 3 celebrated the simultaneous delivery of three 777s — two 777-300ERs and one 777 Freighter — marking the entry of the 150th 777 into Emirates’ fleet. The delivery marks the first tim...
 
 

U.S. Air Force selects Chromalloy for F108 gas turbine engine module repairs

Chromalloy announced Sept. 2 that it has been selected by the U.S. Air Force to provide repairs on low pressure turbine modules for the F108 aircraft engine fleet, in a contract valued at up to $74 million. The one-year agreement was contracted by the Tinker Air Force Base in Oklahoma and includes four one-year options...
 
 
raytheon-colorado

Raytheon expanding in Colorado Springs

Raytheon will speed up growth of its Colorado Springs presence after signing a $700 million multi-year indefinite-delivery/indefinite-quantity contract to support operations at NORAD’s Cheyenne Mountain Complex. Under the...
 




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=""> <s> <strike> <strong>