In a breakthrough for the hunt for life on Mars, a NASA robot has detected the most complex organic matter yet from 3.5 billion-year-old rocks on the surface of the Red Planet, scientists said Thursday. The unmanned Curiosity rover has also found increasing evidence for seasonal variations of methane on Mars, indicating the source of the gas is likely the planet itself, or possibly its subsurface water. While not direct evidence of life, the compounds drilled from Mars’ Gale Crater are the most diverse array ever drilled from the surface of the planet since the robotic vehicle landed in 2012, experts say.
