Colonies of microorganisms found thriving under rocks at the north and south poles are evidence that life can exist in harsh areas on Earth which may mimic conditions on Mars, scientists said Wednesday.
“This shows us that places we may think of as extreme — for example, other planets, like Mars — could nurture surprising habitats for life,” Charles Cockell, a microbiologist with the British Antarctic Survey, said in an interview. “No one has described these microbes as actually living under these rocks before.”
Antarctica and the Arctic region are thought to have the most Marslike environments on Earth, and scientists study the polar areas to gain a better understanding of the Red Planet.
Microbes in polar deserts
The rocks in the research reported in Thursday's issue of the journal Nature were collected from Cornwallis Island and Devon Island in the Arctic, and from Mars Oasis on Alexander Island on the Antarctic Peninsula.
The areas are considered polar deserts because of their extreme conditions. Violent winds and ultraviolet light make the polar environment especially harsh.
Less than 1.2 percent of the poles is covered in vegetation. About 95 percent of the rocks the researchers studied were colonized by microbes.
“The poles are not the barren wilderness, devoid of life, as we previously thought,” said Cockell.
Microorganisms can live under quartz and translucent rocks in hot deserts because enough light gets through. But Cockell and scientists at the Scripps Institution of Oceanography in California did not expect what they found in the polar regions because most of the rocks are opaque so they block light.
Life in the cracks
The unusual environment for life is created by the thawing and freezing that occurs, which allow the rocks to move slightly.
“It’s just enough to create cracks around the edges of the rocks where light can penetrate underneath them. That’s how completely opaque rocks are colonized on their underside by photosynthetic microbes,” Cockell said.
“It shows there are habitats in the polar desert that are very productive and not necessarily visible to the naked eye. One wonders about wandering around Mars and picking up rocks and looking underneath them,” he added.