
The image shows the orbits of the Martian moons Phobos and Deimos and the spread of potential particle trajectories from an asteroid impact on Mars.
"We are talking little green microbes, not little green men," said Jay Melosh, a distinguished professor of earth, atmospheric and planetary sciences and physics and aerospace engineering at Purdue. "A sample from the moon Phobos, which is much easier to reach than the Red Planet itself, would almost surely contain Martian material blasted off from large asteroid impacts. If life on Mars exists or existed within the last 10 million years, a mission to Phobos could yield our first evidence of life beyond Earth."
Melosh led a team chosen by NASA's Planetary Protection Office to evaluate if a sample from Phobos could contain enough recent material from Mars to include viable Martian organisms. The study was commissioned to prepare for the failed 2011 Russian Phobos-Grunt mission, but there is continued international interest in a Phobos mission, he said. It will likely be a recurring topic as NASA reformulates its Mars Exploration Program.












