New data from NASA's Mars Odyssey orbiter supports the long-debated theory that Mars once (or twice) had vast frozen oceans on its surface. The location of certain mineral deposits suggests massive erosion and ancient shorelines. A group of researchers now believes Mars had at least two oceans - one about three and a half billion years ago that was 20 times the size of the Mediterranean and a smaller one about two billions years ago.
"These were not like the oceans we know," says [researcher Victor] Baker. "These were transient bodies that existed long enough to accumulate sediment", but were not present for billions of years of geologic history, as Earth's oceans have been [New Scientist].
The Mars Odyssey orbiter identified the mineral deposits using a gamma-ray spectrometer, which
can detect elements a third of a metre below Mars's surface. It found enriched potassium, thorium and iron, lying in shoreline-type ...
