Friday, August 12, 2016

Habitable Venus?

Once, probably. A long time ago, Venus apparently was...colder than Earth. Not by a lot. By a few degrees.

With days and nights of two months each it would have been a very different world from ours. It would have had shallow oceans...but it would likely have had life.

At this time the sun was about 30 percent dimmer than it is today. About 715 million years ago, the brightening sun would have sent too much energy to Venus, causing the runaway greenhouse effect that produced the hellish planet we know today. It was simply too close to the sun to last. (And one day, in a few billion years, as the sun expands, the same thing will happen to Earth, unless we learn planetary engineering and move the entire planet. Most likely by then we'll be extinct or have evolved into something else).