Mars: 'Recent' Rivers on the Red Planet

"Rivers Might Have Flowed Recently on Mars "
Space.com (May 14, 2009)

"Mars is bone dry today. But long, long ago it was wetter and likely had rivers, most scientists agree.

"A new study finds some serious valleys carved by rivers within the last billion years -- much sooner than most similar findings. That's good news for biologists, as water is a key to life as we know it, and the more recently there was liquid water on Mars, the greater the chances for life to have arisen and endured...."

Not everybody thinks of "recently" and "within the last billion years" as meaning the same thing - but on a planetary time scale, something that happened less than 1,000,000,000 years ago is, in some senses, practically current events.

The recently cut river channels aren't the big features of 3,500,000,000 or so years ago: but they indicate that Mars had water, in significant quantity, much more recently than we thought a few years ago.

Life may or may not exist on Mars - but it isn't quite as much of a long shot now, as we thought before these findings.

Other posts, about "Mars, Mostly."