Planetary scientists have claimed "large regions" of Mars are habitable for terrestrial life.
An international team, led by the Australian National University, compared models of temperature and pressure conditions on Earth with those on Mars to estimate how much of the distant planet was liveable for Earth-like organisms.
While just one per cent of Earth's volume -- from core to upper atmosphere -- was occupied by life, the scientists said their world-first modelling showed three per cent of Mars was habitable, though most of it was underground.
"What we tried to do, simply, was take almost all of the information we could and put it together and say 'is the big picture consistent with there being life on Mars?'. And the simple answer is yes. There are large regions of Mars that are compatible with terrestrial life," the media quoted Charley Lineweaver, who led the team, as saying.
Where previous studies had taken a "piecemeal" approach by examining particular sites on Mars for potential signs of life, Lineweaver said that his research was a "comprehensive compilation" of the entire planet using decades of data.
Mars' average surface temperature is minus 63 degrees Celsius.
Lineweaver said his study was "the best estimate yet published of how habitable Mars is to terrestrial microbes" and a significant finding given mankind had evolved from microbial life.
The findings have been published in the latest edition of the 'Astrobiology' journal.
