Join Donate

The Bruce Murray Space Image Library

Possible sources and sinks for methane on Mars

Possible sources and sinks for methane on Mars

Click to view full image

NASA / JPL / SAM-GSFC / U. Michigan

Possible sources and sinks for methane on Mars
This illustration portrays possible ways that methane might be added to Mars' atmosphere (sources) and removed from the atmosphere (sinks). A molecule of methane consists of one atom of carbon and four atoms of hydrogen. Comet dust brings organic chemicals to Mars from space. Ultraviolet radiation (UV) from the Sun can induce reactions that generate methane from these chemicals, which is probably responsible for a low, global background level of methane everywhere in the atmosphere of Mars. UV can also generate methane from organic materials in the Martian surface. Other possible sources for methane on Mars include reactions between water and olivine, and, hypothetically, microbes. Methane generated underground in the distant or recent past might be stored within lattice-structured methane hydrates called clathrates, and released by the clathrates at a later time, so that methane being released to the atmosphere today might have formed in the past.

Winds on Mars can quickly distribute methane coming from any individual source, reducing localized concentration of methane. Methane can be removed from the atmosphere by sunlight-induced reactions (photochemistry). These reactions can oxidize the methane, through intermediary chemicals such as formaldehyde and methanol, into carbon dioxide, the predominant ingredient in Mars' atmosphere.

Most NASA images are in the public domain. Reuse of this image is governed by NASA's image use policy.

Original image data dated on or about December 16, 2014

Explore related images: explaining science, Mars

Comments & Sharing
More Images
Bill Nye and people
Let's Change the World

Become a member of The Planetary Society and together we will create the future of space exploration.

Join Today

Bruce Murray and Carl Sagan
Pretty Pictures

Support the Bruce Murray Space Image Library and help us share the wonders of other worlds.


"We're changing the world. Are you in?"
- CEO Bill Nye

I'm In!