Hows this new? Methane on Mars was detected over 5 years ago.
The fact that it remains in the atmosphere means something is replenishing the gas. This is news. Very interesting news. Mars has been thought to have an atmospehere
in a state of gaseous equilibrium unlike Earth's highly dynamic atmosphere which is in a state of disequilibrum (in fact, remotely detecting the state of equilibrium of planetary atmospheres via spectroscopic analysis is one way to build assumptions about
the likelihood of active geological and biological systems operating on the planet in question...). Mars has been thought to be geologically "dead" as well. Methane gas entering the Martian atmosphere means it's not just the cold red rock we thought it was.