There probably is life on Mars and it may well be as we know it.
Scientists believe there is bacteria clinging onto existence far beneath the frozen deserts of the Red Planet.
And it is likely to be similar to the simple microbes that exist in the deep ice-bound lakes of Antarctica.
Scientists say Mars and the Earth ‘almost certainly’ seeded each other with life billions of years ago when both planets were battered with huge asteroid strikes - sending fragments of them both into space.
Biologists think discovering the life on Mars could show us how life first began to stir on our own world.
Alfred McEwen, professor of planetary geology at the University of Arizona, said: “The billion-year-old record of life on Earth is largely lost, but on Mars it is still preserved.
“There is probably a connection between life on Mars and life on Earth.
“So the search for ancient life on Mars may really be the search for the origin of life on Earth.”
Professor McEwan is the principal investigator on Nasa’s HiRISE telescope which is orbiting Mars and producing detailed images of the surface.
NASA has already identified underground water ‘wicking’ to the surface of the planet and samples collected by the Mars rovers have detected complex organic compounds.
Professor McEwen told a conference in Tenerife attended by Professor Stephen Hawking and other Nobel laureates that life probably still survives in pockets below the surface where it would be warmer and they were sheltered from cosmic radiation.
“At the depth of a few kilometres it’s warm enough to keep H2O in a liquid state.
“So if there was ever life on Mars in the past, it probably survives to the present day in these underground pockets.
“Mars is not very far away; Martian rocks from impacts can easily reach Earth; probably Earth rocks also reached Mars from impacts in the past.
“Life began on this planet about four billion years ago when there were lots of big-impact events, microorganisms could survive a trip between Earth and Mars.
“This raises the question: did life arise on Earth and get transported to Mars or was it the other war round.
“I think life was probably present on Mars from this exchange, and probably persists underground today.”
Average Distance from Sun
Earth: 93 million miles
Mars: 142 million miles
Diameter
Earth: 7,926 miles
Mars: 4,220 miles
Length of Year
Earth: 365.25 Days
Mars: 687 Earth Days
Length of Day
Earth: 23 hours 56 minutes
Mars: 24 hours 37 minutes
Temperature Average
Earth: 57 degrees F
Mars: -81 degrees F
Atmosphere
Earth: Nitrogen, oxygen, argon, others
Mars: Mostly carbon dioxide, some water vapour