January 15, 2009
Methane: Evidence Of Life On Mars? (UPDATE)
NASA TV's broadcast on Thursday confirmed that Mars is, indeed, an active planet in our solar system, as the first definitive detection of methane gas has been released into the red planet's atmosphere.
Michael Meyer, the lead scientists of the Mars program at NASA, headed a broadcast panel of NASA and University scientists who stated that it is not yet known whether the methane sources were produced geologically or biologically"”suggesting microbial activity of an alien nature.
Michael Mumma, of NASA's Goddard Space Flight Center in Greenbelt, Md., stated that the team used spectrometer instruments attached to several telescopes to confirm the methane detection.
The methane releases were recently generated and released from four discreet vents on the surface of the planet.
Scientists say methane is a molecule not expected to be found on Mars and it is likely that the sources were produced through geological processes such as the oxidation of iron (serpentinization) or by microscopic Martian life well below the planet's surface.
One of the panelists, Geronimo Villanueva, a planetary scientist and astrobiologist at the Goddard Space Flight Center, stated that the methane released currently could have been produced recently or it could be an ancient source of the gas trapped in ice cages known as clathrates.
"It could even be gas below a subsurface ice layer," he added.
The panel acknowledged they do not yet know whether the methane sources seep out slowly or are emitted forcefully, but it is likely that ancient pockets of the gas could build up pressure over time to be released with intense energy.
Whether geological or biological, no compelling evidence points to which process caused the methane, according to Lisa Pratt, professor of geological sciences, Indiana University in Bloomington.
However, she stated that this new discovery is one of many recent pieces of evidence pertaining to the possible existence of liquid water on Mars.
Liquid water is necessary for all known forms of life, as are energy sources and a supply of carbon.
"Methane is quickly destroyed in the Martian atmosphere in a variety of ways, so our discovery of substantial plumes of methane in the northern hemisphere of Mars in 2003 indicates some ongoing process is releasing the gas," said Mumma, lead author of a paper describing this research that will appear in Science Express on Thursday.
Mumma said it might be possible for microorganisms similar to those found on Earth to survive for billions of years below the permafrost layer on Mars, where water is liquid, radiation supplies energy, and carbon dioxide provides carbon.
"Gases, like methane, accumulated in such underground zones might be released into the atmosphere if pores or fissures open during the warm seasons, connecting the deep zones to the atmosphere at crater walls or canyons," he added.
He said that while there is not enough data to confirm whether the methane comes from a biological or geological source, "it does tell us the planet is still alive, at least in a geologic sense."
Mumma continued: "It is as if Mars is challenging us, saying, 'hey, find out what this means.'"
Image 1: Scientists don't yet know enough to say with certainty what the source of the Martian methane is, but this artist's concept depicts a possibility. In this illustration, subsurface water, carbon dioxide and the planet's internal heat combine to release methane. Although we don't have evidence on Mars of active volcanoes today, ancient methane trapped in ice "cages" might now be released. Credit: NASA/Susan Twardy
Image 2: This image shows concentrations of Methane discovered on Mars. Credit: NASA
On the Net:
- Streaming Video
- NASA Mars Exploration Program
- Goddard Space Flight Center
- Indiana University
- Science Express