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Martian Methane

June 23, 2015

Every few months, the region around the Curiosity Mars rover seems to get a bit “gassy” — it emits puffs of methane, the main ingredient in natural gas.

Here on Earth, methane is produced mainly by the decomposition of dead plants, and in the digestive tracts of cattle and other animals. Because of that biological origin, finding it on other worlds could indicate the presence of life. On the other hand, methane can also be produced by volcanoes and other geological processes, so it’s not a guarantee of extraterrestrial life.

In recent years, ground-based telescopes have detected small amounts of methane in the atmosphere of Mars. So has the Mars Express orbiter. These observations created a debate about the source of the methane: geology versus biology. Some argue that it’s created by microbes living below the surface, while others say it most likely comes from chemical reactions in the rocks and dirt.

Curiosity landed on Mars almost three years ago. Its instruments can analyze the Martian atmosphere for methane and other key compounds.

At first, it found almost no methane at its landing site inside a large crater. Since then, though, it’s detected two jumps in the amount of methane — each to about 10 times the normal level.

But the rover’s instruments can’t determine the source of the methane. So it’ll take more work to determine whether those outbursts come from living Martians.


Script by Damond Benningfield, Copyright 2015

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