A Third of Mars Could Have Been Underwater

Matt_dk writes "An international team of scientists who analyzed data from the Gamma Ray Spectrometer onboard NASA's Mars Odyssey reports new evidence for the controversial idea that oceans once covered about a third of ancient Mars. 'We compared Gamma Ray Spectrometer data on potassium, thorium and iron above and below a shoreline believed to mark an ancient ocean that covered a third of Mars' surface, and an inner shoreline believed to mark a younger, smaller ocean.'"

Comments

Why controversial?

[Tacubaruba]

Haven't we gotten past the point where the idea of Mars once having lots of water is controversial? I mean, it seems as if every new piece of evidence points in that direction, so what exactly still makes it controversial?