A FROZEN sea on Mars may harbour life several metres below the surface, according to research by British scientists.

The 560-mile-wide Elysium sea contains ancient ice that appeared within the last five million years.

Dormant cell-life may have survived because, trapped in the ice, it would only have been exposed to the planet's lethal radiation for a relatively short period of time.

Water also provides a good shield against cosmic radiation and is 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 will be necessary to dig deep - up to several metres and beyond the range of current robotic instruments.

Radiation

Even in the Elysium ice, radiation would have killed off any living organisms any closer to the surface.

Lewis Dartnell, from University College London, led the British and Swiss team.

He said: "Finding hints 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 we can warm up, feed nutrients and reawaken for studying. Finding life on Mars depends on liquid water surfacing on Mars, 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 of Mars for that long."