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Ancient Mars was covered in ice sheets meaning life was even more likely, scientists say

The western edge of the Devon ice cap on the Canadian Arctic Archipelago. The similarity between many Martian valleys and the subglacial channels on Devon Island in the Canadian Arctic motivated the authors to conduct their comparative study. -  Grau Galofre/ASU
The western edge of the Devon ice cap on the Canadian Arctic Archipelago. The similarity between many Martian valleys and the subglacial channels on Devon Island in the Canadian Arctic motivated the authors to conduct their comparative study. - Grau Galofre/ASU

Ancient Mars was covered in ice sheets, according to a new study, adding support to the likelihood that life once existed on the planet.

Previous studies have suggested that Mars’ valleys were formed by flowing rivers and its climate would have been warm and wet.

But scientists now claim the Red Planet would have in fact looked more like the current-day Canadian Arctic, covered in huge glaciers.

These glaciers make the chances of life on the planet even more likely, as they would have acted as protection from the sun’s radiation for any organisms living underneath.

The new research, published in Nature Geoscience, suggests Mars’ climate was cold and it’s ancient valleys were carved by water melting underneath the glaciers.

Lead author Dr Anna Grau Galofre, of Arizona State University, said: "Climate modelling predicts Mars' ancient climate was much cooler during the time of valley network formation.

"We tried to put everything together and bring up a hypothesis that hadn't really been considered - that channels and valleys networks can form under ice sheets."

This is part of the natural drainage system beneath an ice sheet when water accumulates at the base, she explained.

A composite view of the tributary valley on planet Mars that feeds into Valles Marineris, the "Grand Canyon of Mars", is seen in this video image released by NASA in 2006 - REUTERS/NASA
A composite view of the tributary valley on planet Mars that feeds into Valles Marineris, the "Grand Canyon of Mars", is seen in this video image released by NASA in 2006 - REUTERS/NASA

A sheet of ice would lend more protection for living organisms and stability to underlying water, as well as providing shelter from solar winds.

The discovery follows the launch of NASA's rover Perseverance last week, which is due to land in February. The rover will drill into rocks in the hope of discovering any signs of life.

Dr Galofre and colleagues analysed valleys on Mars to determine the different ways in which they could have been shaped.

They found most were similar to those eroded by either rivers or water in channels beneath ice sheets in the Canadian Arctic Archipelago.

Dr Grau Galofre said: "Understanding the climate in the first billion years of Mars' history is important in determining whether the planet was ever habitable.”

The researchers looked at over 10,000 Martian valleys using an algorithm to infer their underlying erosion processes.

“These results are the first evidence for extensive subglacial erosion driven by channelized [sic] meltwater drainage beneath an ancient ice sheet on Mars,” said co-author Mark Jellinek, professor at the University of British Columbia in Canada.