Mars: 'Strongest evidence' planet may have supported life, scientists say
Minerals found underground on Mars are the "strongest evidence yet" that the planet may have supported life, according to new research.
The team, led by the Natural History Museum in London and the University of Aberdeen, said the ingredients for life could have been in a zone up to 5km down for much of the planet's history.
They used data from the US space agency (Nasa) and European Space Agency (Esa).
Nature Geoscience has published the research.
The team said the research backed up the existing theory that Mars could have supported life due to micro-organisms hidden beneath the surface.
They said that when meteorites strike the surface of Mars, they act as natural probes, bringing up rocks from far below.
The McLaughlin Crater is described as one such area of interest in the study.
Dr Joseph Michalski, lead author and planetary geologist at the Natural History Museum, said: "We don't know how life on Earth formed but it is conceivable that it originated underground, protected from harsh surface conditions that existed on early Earth.
"However, the early geological record of Earth is poorly preserved so we may never know what processes led to life's origin and early evolution.
"Whether the Martian geologic record contains life or not, analysis of these types of rocks would certainly teach us a tremendous amount about early chemical processes in the solar system.
"In this paper, we present a strong case for exploring the subsurface, as well as the surface.
"But I don't personally think we should try to drill into the subsurface to look for ancient life. Instead, we can study rocks that are naturally brought to the surface by meteor impact and search in deep basins where fluids have come to the surface."
Co-author Prof John Parnell, geochemist at the University of Aberdeen, added: "This research has demonstrated how studies of Earth and Mars depend on each other.
"It is what we have observed of microbes living below the continents and oceans of Earth. They allow us to speculate on habitats for past life on Mars, which in turn show us how life on the early Earth could have survived.
"We know from Earth's history that planets face traumatic conditions such as meteorite bombardment and ice ages, when the survival of life may depend on being well-below ground.
"So it makes sense to search for evidence of life from that subsurface environment, in the geological records of both Earth and Mars.
"But it's one thing to do that on Earth - we need to be clever in finding a way to do it on Mars."