What are the most likely sources of the methane gas detected in the Martian atmosphere by the Mars Express orbiter and the Curiosity rover?
A) biological activity only
B) biological or geological activity
C) comet impacts only
D) geological activity only

Question

Quizplus · Accepted Answer

The most likely sources of methane gas in the Martian atmosphere are both biological and geological activity. While it is possible that some of the methane could be released from comets impacting the planet, this is not the most probable explanation based on available evidence. Both the Mars Express orbiter and the Curiosity rover have detected methane in the atmosphere, which suggests that the gas is being produced and released continuously, rather than by rare comet impacts. Evidence suggests that past and/or present biological activity (such as microbial metabolism) and geological processes (such as serpentinization) could be the primary sources of Martian methane.

What Are the Most Likely Sources of the Methane Gas