A surprising and mysterious belch of methane gas on Mars hints at possible microbial life underground, but also could come from changes in rocks, a new NASA study found. The presence of methane on Mars could be significant because by far most of the gas on Earth is a byproduct of life — from animal digestion and decaying plants and animals. Past studies indicated no regular methane on Mars. But new research using three ground-based telescopes confirmed that nearly 21,000 tons of methane were released during a few months of the late summer of 2003.
