Meteorites may reveal secrets of life on Mars

Researchers have examined a meteorite that formed on Mars more than a billion years ago in an effort to determine if conditions were ever favourable for life to sustain on the red planet.
"These meteorites contain water-related mineral and chemical signatures that can signify habitable conditions," said Michigan State University professor, Michael Velbel.
The problem, Velbel said, is that most meteorites that originated on Mars arrived on Earth so long ago that now they have characteristics that tell of their life on Earth, obscuring any clues it might offer about their time on Mars.
"The trouble is by the time most of these meteorites have been lying around on Earth they pick up signatures that look just like habitable environments, because they are. Earth, obviously, is habitable.

"If we could somehow prove the signature on the meteorite was from before it came to Earth, that would be telling us about Mars," Velbel said.
Specifically, the team found mineral and chemical signatures on the rocks that indicated terrestrial weathering - changes that took place on Earth.

The identification of these types of changes will provide valuable clues as scientists continue to examine the meteorites.
"Our contribution is to provide additional depth and a little broader view than some work has done before in sorting out those two kinds of water-related alterations - the ones that happened on Earth and the ones that happened on Mars," Velbel said.

The meteorite that Velbel and his colleagues examined - known as a nakhlite meteorite - was recovered in 2003 in the Miller Range of Antarctica. About the size of a tennis ball and weighing in at one-and-a-half pounds, the meteorite was one of hundreds recovered from that area.
Velbel said past examinations of meteorites that originated on Mars, as well as satellite and Rover data, prove water once existed on Mars, which is the fourth planet from the sun and Earth's nearest Solar System neighbour.
"However, until a Mars mission successfully returns samples from Mars, mineralogical studies of geochemical processes on Mars will continue to depend heavily on data from meteorites." he said.