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.
The once-flat shorelines
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.
How do the planetary scientists arrive at that figure, 2 billion years? Why not 20,000 years or 2 million years? Does anyone know on what they base this conclusion?
Bill