Methane finally confirmed on Mars. The new research doesn’t say what might produce the methane, but identifies the likely source as Aeolis Mensae, a region known to be on a tectonic transition zone. Though geological processes could be responsible, on Earth, over 90% of methane is produced by life.

See the source article by following the link below:
Methane finally confirmed on Mars. The new research doesn’t say what might produce the methane, but identifies the likely source as Aeolis Mensae, a region known to be on a tectonic transition zone. Though geological processes could be responsible, on Earth, over 90% of methane is produced by life.