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The existence of an ancient, frigid ocean on Mars that was surrounded by glaciers could explain the unusual minerals found making up the northern lowlands of the Red Planet, a new study suggests.
These findings add new evidence to the idea that ancient Mars was once cold and wet, not cold and dry nor warm and wet as is often argued.
Astrobiologist Alberto Fairén at the SETI Institute and NASA Ames Research Center and his colleagues investigated why the early crust of the northern Martian lowlands apparently lacks a mineral group called phyllosilicates when compared to similarly aged crust in the planet's southern lowlands. These minerals are common in marine sediments on Earth.
Their climatic and geochemical models suggest that if a northern ocean existed on Mars, it would have been close to freezing. Moreover, features around the proposed ocean basin are consistent with the presence of large glaciers, such as underwater stretches of rocky debris known as moraines. Near-freezing temperatures and large glaciers would prevent phyllosilicates from forming and depositing in a lowland ocean basin.
"Our multidisciplinary analyses offer an explanation for the existence of an ocean in the past of Mars which is consistent with the mineralogy detected so far by orbiters and landers," said Fairén, lead author of a study appearing online Aug. 28 in the journal Nature Geoscience. "If there were oceans on Mars, they were cold glacial, similar to the polar seas on Earth. The coasts would be rimmed by glaciers, and portions of the ocean would be ice-covered."
There are currently two leading ideas for what the climate of ancient Mars might have been like.
http://www.space.com/12761-ancient-mars-cold-ocean-evidence.html
These findings add new evidence to the idea that ancient Mars was once cold and wet, not cold and dry nor warm and wet as is often argued.
Astrobiologist Alberto Fairén at the SETI Institute and NASA Ames Research Center and his colleagues investigated why the early crust of the northern Martian lowlands apparently lacks a mineral group called phyllosilicates when compared to similarly aged crust in the planet's southern lowlands. These minerals are common in marine sediments on Earth.
Their climatic and geochemical models suggest that if a northern ocean existed on Mars, it would have been close to freezing. Moreover, features around the proposed ocean basin are consistent with the presence of large glaciers, such as underwater stretches of rocky debris known as moraines. Near-freezing temperatures and large glaciers would prevent phyllosilicates from forming and depositing in a lowland ocean basin.
"Our multidisciplinary analyses offer an explanation for the existence of an ocean in the past of Mars which is consistent with the mineralogy detected so far by orbiters and landers," said Fairén, lead author of a study appearing online Aug. 28 in the journal Nature Geoscience. "If there were oceans on Mars, they were cold glacial, similar to the polar seas on Earth. The coasts would be rimmed by glaciers, and portions of the ocean would be ice-covered."
There are currently two leading ideas for what the climate of ancient Mars might have been like.
http://www.space.com/12761-ancient-mars-cold-ocean-evidence.html
