Life on Mars could be surviving in an area deep underground

The presence of life deep in our own rocks begs the obvious. Can they live in all our planets?

We may well be surprised because we have all been looking at the surface which is naturally scoured clean.

We will be going to all these places.  the first thing we will do is locate an exposed cliff of clean rock and drive on in.  This alone protects us from radiation and temperature shifts.

And we do not have to bring materials to do this.  Raw rock is good enough.

Life on Mars could be surviving in an area deep underground

The Acidalia Planitia region of the Red Planet might have all the requirements for methane-burping bacteria to exist beneath the surface

By Jonathan O’Callaghan

29 November 2024

https://www.newscientist.com/article/2458263-life-on-mars-could-be-surviving-in-an-area-deep-underground/

The Acidalia Planitia, the darker region towards the top right of this image of Mars, may host bacteria deep beneath its rocky surface

A specific area on Mars has been identified as a potential location for current life – with the organisms living far beneath the surface.

Andrea Butturini at the University of Barcelona and his colleagues investigated possible locations on Mars that could host living organisms, focusing on areas that might have the right amounts of water, heat and energy necessary for life to exist.

Taking data from the multitude of orbiters and rovers that have visited Mars, the researchers found that Acidalia Planitia – a 3000-kilometre-wide plain in the northern hemisphere of Mars – seems to have the right conditions for methanogens, methane-producing bacteria, an estimated 4.3 to 8.8 kilometres beneath the surface.

“[It is] a promising target area for future missions in the search for extant life in Mars’ subsurface,” the researchers write.

Methanogens on Earth are found in a variety of environments including in wetlands and deep in the oceans. Some of these locations, such as extremely salty pockets of water at the sea floor, are “analogs of a hypothetical habitable Martian subsurface”, according to Butturini and his colleagues.

The low pressure and temperature at the surface of Mars – NASA’s Perseverance rover experienced a range of about -93 to 17°C (-136 to 62°F) – make the possibility of life there remote. But in the subsurface, remnant water from the planet’s past, plus heat and chemical energy produced by the radioactive decay of elements such as thorium left over from the planet’s formation, could provide the ingredients for life to survive.

“There’s enough energy to, in theory, fuel life very slowly,” says Jon Telling at Newcastle University, UK. “The dividing times of bacteria might be hundreds of years,” he says, whereas bacteria in laboratories on Earth “under ideal conditions can divide and grow in 20 minutes”.

Using data from Mars orbiters, Butturini and his colleagues identified several regions on Mars as having an abundance of thorium that could provide this energy. Matching this with the distribution of ice picked up by missions like China’s Zhurong rover, the “most robust target area is the southern Acidalia Planitia at mid latitude”, they write, specifically between 4.3 and 8.8 kilometres deep, where the conditions could support liquid water mixed into the Martian soil because of the predicted temperature of 0 to 10°C (32 to 50°F).

“The potential for subsurface sites to host an ecosystem independent of the surface is not science fiction,” says Telling.

However, accessing such a deep location to see if there is actually life there would be extremely difficult. “We can barely do that on Earth,” says Telling. “It’s going to be hard to drill down to those levels without major crewed missions.”

The upcoming Rosalind Franklin rover from the European Space Agency (ESA), due to launch in 2028, will include a drill to dig into the surface, but only down to 2 metres. Whether any methanogens several kilometres below the surface would produce evidence of life at this shallower depth is “really unknown”, says Kevin Olsen at the University of Oxford.

So far, searches for methane in the Martian atmosphere from biological sources using ESA’s Trace Gas Orbiter spacecraft have been unsuccessful. “The methane observations are sporadic,” says Olsen. “It’s hard to say where they’re coming from.”

Yet identifying potentially habitable locations on Mars is still useful for future study, says Telling. “If you want to look for life alive today on Mars, you’ve got to look deep down,” he says.