Sur­face scars on Mars sim­i­lar to Canada’s High Arc­tic: study

The Province - - NEWS - HINA ALAM

The deep val­leys scarred into the sur­face of Mars un­der thick sheets of ice show that the planet once mir­rored the Cana­dian High Arc­tic, says a new study.

Pub­lished Mon­day in the jour­nal Na­ture Geo­science, the study says many of the val­ley net­works carved into the sur­face of Mars were formed by wa­ter melt­ing be­neath glacial ice. It means there were fewer free-flow­ing rivers than pre­vi­ously thought.

Study au­thor Anna Grau Galofre, a for­mer Univer­sity of B.C. PhD stu­dent in the de­part­ment of earth, ocean and at­mo­spheric sciences, said that about 3.5 bil­lion years ago, the Mar­tian sur­face looked like the sur­face of Canada 20,000 years ago.

“We’re talk­ing about a planet that’s painted like a brother of Earth,” she said.

Grau Galofre and her team com­pared sur­face data of Mars with that of Devon Is­land in the Cana­dian Arc­tic. The study de­scribes Devon Is­land as a cold, dry, po­lar desert, where the glaciers and their re­treat im­i­tate what took place on Mars bil­lions of years ago.

“Imag­ine ice sheets that are kilo­me­tres thick, re­ally, re­ally thick,” she said. “If you were to just lift the ice sheet and see be­low, you would see a land­scape. And this land­scape is con­sti­tuted of sev­eral dif­fer­ent chan­nels, ex­panded path­ways like the plumb­ing of the ice.”

What this tells sci­en­tists is that while there may have been a warm and wet Mars on which there was rain­fall, it’s far more likely that the planet’s sur­face re­sem­bled that of the Cana­dian Arc­tic, she said.

“It is like a time evo­lu­tion of the cli­mate that we’re look­ing at here. There were the warm and wet pe­ri­ods that talked about the oceans. And there were the cold and icy pe­ri­ods,” Grau Galofre said.

This could mean that the cli­mate on Mars ei­ther changed slowly through time from a cooler to a warmer pe­riod or the other way around, she said.

The new find­ings bring up an “in­ter­est­ing dis­cus­sion point” about life on Mars, Grau Galofre said: “That’s ac­tu­ally not a bad thing in terms of an en­vi­ron­ment to sus­tain life.”

Lake Vos­tok on Antarc­tica is cov­ered by a thick sheet of ice but has plenty of life, such as bac­te­ria, she said. “And they have been there for a long time, up to a mil­lion years, pretty much iso­lated by the ice sheet.”

The ice guar­an­tees the crea­tures get wa­ter and also pro­vides a sta­ble en­vi­ron­ment, es­pe­cially on a planet like Mars, which can have sear­ing days and freez­ing nights, said Grau Galofre.

The ice sheet also pro­tects life from so­lar ra­di­a­tion, she added.

The study could be ex­panded to in­clude the Jezero Crater, where NASA’s Per­se­ver­ance is sched­uled to land on Mars be­cause it may have once har­boured life, she said.

Mars is the first and ob­vi­ous place to start look­ing for life be­cause it still has north­ern and south­ern ice caps, as well as a small frac­tion of wa­ter in the at­mos­phere, Grau Galofre said.

Ev­i­dence of wa­ter shows there is life or there was a time when life ex­isted, she said.

— CP FILES

A study pub­lished in the jour­nal Na­ture Geo­science de­scribes Devon Is­land as a cold, dry, po­lar desert, where the glaciers and their re­treat im­i­tate what took place on Mars bil­lions of years ago.

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