Something is recycling the methane on Mars

Research results posted today [pdf] at the European Planetary Science Congress show that the methane in Mars’s atmosphere is seasonally variable and far more short-lived than predicted, disappearing in less than a year. Some process, therefore, must be both using it and replenishing it. On Earth, that’s almost always done by some form of life process. Key quote by one of the scientists, from the press release:

“Only small amounts of methane are present in the martian atmosphere, coming from very localised sources. We’ve looked at changes in concentrations of the gas and found that there are seasonal and also annual variations. The source of the methane could be geological activity or it could be biological ­ we can’t tell at this point.”

The image below shows the three regions (in yellow) where the methane is concentrated.

Mars methane locations

Avalanches on Mars

Saturday’s weekly dump of publications from the American Geophysical Union also included a paper that showed visual proof of avalanches on Mars! In this case, the location is Russell Crater, “a large crater in the southern hemisphere that exposes a large dune field in its center.” The avalanches occur because a frost layer made up of dry ice and a little bit of frozen water builds up on the crest of the dunes. When that frost melts, dark streaks about three to six feet wide and about 150 feet long appear, flowing downhill. The scientists believe these are avalanches made up of “a mixing of sand, dust, and unstable CO2 gas.”

wide shot of before and after
Before and after shots of the dark streaks flowing down the dune.

close-up, before and after
Close-ups of the streaks, before and after.

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