Mystery solved: Mars had large oceans
Warping of Martian rock has hidden clear evidence of oceans
Since 1991, planetary scientists have floated the idea that Mars once harbored vast oceans that covered roughly one-third of the planet. Two long shore-like lips of rock in the planet's northern hemisphere were thought to be the best evidence, but experts argued that they were too "hilly" to describe the smooth edges of ancient oceans.
The view just changed dramatically with a surprisingly simple breakthrough.
The once-flat shorelines were disfigured by a massive toppling over of the planet, scientists announced today. The warping of the Martian rock has hidden clear evidence of the oceans, which in any case have been gone for at least 2 billion years.
"This really confirms that there was an ocean on Mars," said Mark Richards, a planetary scientist at the University of California at Berkeley and co-author of the study, which is detailed in the June 14 issue of the journal Nature.
Twin shores
Two major shorelines exist on Mars, each thousands of miles long — one remaining from the older Arabia Ocean, and another from the younger Deuteronilus Ocean, said study co-author Taylor Perron of UC Berkeley.
"The Arabia would have contained two to three times the volume of water than in the ice that covers Antarctica," Perron told SPACE.com.
Somewhere along the way to toppling over 50 degrees to the north, Mars probably lost some of its water, leaving the Deuteronilus Ocean's shoreline exposed. "The volume of water was too large to simply evaporate into space, so we think there is still some subterranean reservoirs on Mars," Perron said.
The remaining sea would have been located in the same lowland plain as the Arabia Ocean, but almost 40 degrees to the north. ....