Science
Related: About this forumNASA Goddard Instrument Makes First Detection of Organic Matter on Mars
(Please note, source is NASA.gov. Copyright concerns are nil.)
http://www.nasa.gov/content/goddard/mars-organic-matter/
December 16, 2014
[font size=3]The team responsible for the Sample Analysis at Mars (SAM) instrument suite on NASA's Curiosity rover has made the first definitive detection of organic molecules at Mars. Organic molecules are the building blocks of all known forms of terrestrial life, and consist of a wide variety of molecules made primarily of carbon, hydrogen, and oxygen atoms. However, organic molecules can also be made by chemical reactions that don't involve life, and there is not enough evidence to tell if the matter found by the team came from ancient Martian life or from a non-biological process. Examples of non-biological sources include chemical reactions in water at ancient Martian hot springs or delivery of organic material to Mars by interplanetary dust or fragments of asteroids and comets.
The surface of Mars is currently inhospitable to life as we know it, but there is evidence that the Red Planet once had a climate that could have supported life billions of years ago. For example, features resembling dry riverbeds and minerals that only form in the presence of liquid water have been discovered on the Martian surface. The Curiosity rover with its suite of instruments including SAM was sent to Mars in 2011 to discover more about the ancient habitable Martian environment by examining clues in the chemistry of rocks and the atmosphere.[/font]
Daniel Glavin of NASA's Goddard Space Flight Center discusses the discovery of organic matter on Mars and other recent results from the MSL Curiosity rover.
Image Credit: NASA Goddard
Download this video in HD formats from NASA Goddard's Scientific Visualization Studio
[font size=3]The organic molecules found by the team were in a drilled sample of the Sheepbed mudstone in Gale crater, the landing site for the Curiosity rover. Scientists think the crater was once the site of a lake billions of years ago, and rocks like mudstone formed from sediment in the lake. Moreover, this mudstone was found to contain 20 percent smectite clays. On Earth, such clays are known to provide high surface area and optimal interlayer sites for the concentration and preservation of organic compounds when rapidly deposited under reducing chemical conditions.
While the team can't conclude that there was life at Gale crater, the discovery shows that the ancient environment offered a supply of reduced organic molecules for use as building blocks for life and an energy source for life. Curiosity's earlier analysis of this same mudstone revealed that the environment offered water and chemical elements essential for life and a different chemical energy source.
"We think life began on Earth around 3.8 billion years ago, and our result shows that places on Mars had the same conditions at that time liquid water, a warm environment, and organic matter," said Caroline Freissinet of NASA's Goddard Space Flight Center in Greenbelt, Maryland. "So if life emerged on Earth in these conditions, why not on Mars as well?" Freissinet is lead author of a paper on this research submitted to the Journal of Geophysical Research-Planets.
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jeff47
(26,549 posts)"Organic compounds" are not necessarily made by lifeforms, despite the name. An organic compound just contains carbon, and is bigger than simple compounds like CO2.
OKIsItJustMe
(19,938 posts)While the team can't conclude that there was life at Gale crater, the discovery shows that the ancient environment offered a supply of reduced organic molecules for use as building blocks for life and an energy source for life.
eppur_se_muova
(36,257 posts)methane is found by the gigaton in the atmospheres of the gas giant planets (Jupiter, Saturn, Uranus, Neptune) and is probably frozen out on most plutinos and comets. There's gigatons of it on Titan in liquid and gaseous form but still no evidence of life there. It was probably present on most of the terrestrial planets initially, but has since escaped (due to low mass of the planet, as on Mercury and Mars) or been transformed into something else (as on Earth and Venus and Mars). So some traces might remain on Mars, most likely as frozen methane hydrate ? Interesting. Not earthshaking.
Eject a carbon atom from the Sun (which happens quite frequently) and it will encounter other atoms and form molecules. By far, the overwhelmingly most likely atom to be encounterd is hydrogen, which makes up most of the Sun. So should the abundance of molecules with absolutely no bonds other than C-H bonds surprise anyone ?
I don't think the general public is sufficiently aware of the formal meaning of the term 'organic' to realize what that term does NOT imply. Journos need to be aware of this and avoid the term unless juxtaposed with clarification. "Carbon-containing molecules" would have done the job.