(editor's note - this is an update to a story we featured at http://www.microbeworld.org/index.php?option=com_jlibrary&view=article&id=2038)
A research team at Johnson Space Centre in Houston has been re-examining a meteorite that hit Antarctica 13,000 years ago, and found the most compelling evidence yet that the planet once harboured bacterial life.
The team says that microscopic crystals found in the rock are almost certainly fossilised bacteria that have many characteristics in common with bacteria found on Earth.
“The evidence supporting the possibility of past life on Mars has been slowly building up during the past decade,” said David McKay, Nasa chief scientist for exploration and astrobiology.
“This evidence includes signs of past surface water including remains of rivers, lakes and possibly oceans and signs of current water near or at the surface.”