Scientists Convinced Mars Had Oceans

While thumbing through Space.com’s “Best Space Discoveries of 2007,” I stumbled upon a gem that I missed this year: “Mystery Solved: Mars Had Large Oceans.”

The idea has been around since 1991 when scientists observed “lips of rock” on Mars that looked an awful lot like shorelines. But there was a catch: the “lips” weren’t smooth enough. They almost resemble mountain ranges. But a new theory explains how the smooth shorelines would have gotten so jagged.

After careful study, planetary scientists at UC Berkley found evidence that Mars “toppled over” millions of year ago. They don’t know why, but one theory is that “a massive change in the distribution of mantle” caused the toppling. However it happened, the event would have caused the once smooth shorelines to warp and bunch up, reports Space.com.

Thus far, scientists have identified two ancient shorelines stretching thousands of miles. Their size suggest oceans big enough to contain up to three-times the volume of ice in Antarctica. I’m not sure why they chose that comparison.

Where did the oceans go? Planetary scientists doubt it all evaporated into space, so they suspect “subterranean reservoirs” remain. What were the oceans made of? The article suggests water, but not whether or not it was salty.

Scientists believe the oceans disappeared about 2 billion years ago.