A FROZEN sea on Mars may harbour life several metres below the surface, according to British scientists.
The Elysium sea, which is 560 miles wide, contains ice that appeared within the past five million years.
Dormant cell-life trapped in the ice would have been exposed for only a relatively short period of time to the lethal radiation that bombards
the planet.
Water also provided a good shield against cosmic radiation and was easier to drill through than rock, said the scientists. They believe Elysium would be an ideal place to search for life - but warned that it would be necessary to dig deep.
Future probes would have to be equipped to drill to a depth of several metres, beyond the range of current robotic instruments. Even in the Elysium ice, radiation would have killed off any living organisms closer to the surface.
Lewis Dartnell, of University College London, who led the British and Swiss team, said: "Finding hints that life once existed - proteins, DNA fragments or fossils - would be a major discovery in itself, but the holy grail for astrobiologists is finding a living cell that we can warm up, feed nutrients and reawaken for studying.
"It just isn't plausible that dormant life is still surviving in the near-subsurface of Mars - within the first couple of metres below the surface - in the face of the ionising radiation field.
"Finding life on Mars depends on liquid water surfacing, but the last time liquid water was widespread on Mars was billions of years ago. Even the hardiest cells we know of could not possibly survive the cosmic radiation levels near the surface."
Other possible sites where life might have survived are newly formed craters.
