October 17, 2012
Methane On Mars Could Lead To Evidence Of Life
Lee Rannals for redOrbit.com - Your Universe Online
"There is an instrument onboard the Curiosity Rover -- which landed on Mars in August -- capable of measuring methane, but the scientists operating that instrument haven't made any public announcements of their results yet," said Chizek in an emailed statement to redOrbit.
"There have been several claims of methane detection in the past decade, but it is controversial whether or not there is really methane on Mars, because we do not understand how it would get there, and scientists' observations suggest that it's varying in abundance on a very quick time scale, which is unexpected."
Chizek said the significance of detecting methane on Mars is exciting, because it could lead to evidence of life.
About 95 percent of the methane in Earth's atmosphere is a product of biology, such as from what cows produce.
"In a couple of my presentations, I show how many cows would be required to equal the amount of methane that astronomers have observed on Mars," she said. "Depending on which observations I am looking at, that number is close to five million cows, or roughly 200,000 tons of methane production."
Astronomers have been able to observe methane on Mars by using telescopes on Earth and spacecraft in orbit around Mars. However, the Earth-based observations are considered controversial because Earth's atmosphere has methane in it, which could interfere with Mars observations.
The instruments on spacecraft orbiting Mars used for methane detections have a lower methane detection capability than the Earth-based instruments. Some scientists consider these instruments to be inadequate for detecting Martian methane.
Chizek said she is using her model to trace back the detected methane to its source location to see if it´s coming from something like a volcanic source, water chemistry interaction, or bacteria living on or near the surface.
"Mars is thought to be a geologically dead planet," she said. "If the methane detections are confirmed, and we do not find any signs of bacterial life, this means there are likely some interesting geological processes happening on Mars that we don't yet know about."
Image 2 (below): NMSU astronomy graduate student Malynda Chizek studies the possible presence of methane gas on Mars using a computer to map the simulated methane distribution during various seasons on the Red Planet. NMSU photo by Audry Olmsted.