For a long time now, evidence has continued to indicate that Mars was once a water world – near-surface groundwater, lakes, rivers, hot springs and, according to some planetary models, even an ancient ocean in the northern hemisphere. That last one in particular has been a subject of intense debate; some scientists see evidence for it while others do not. Even if it was there, it may have been a warm ocean or it may have been colder, like the polar seas here on Earth. The prospect of an ocean of any kind on early Mars is an exciting one, regarding the question of possible life way back then. The argument has swung both ways over the years, but now another new report has been published which comes down on the “yes” side…
See Universe Today for the full article.