Early Earth absorbed more sunlight -- no extreme greenhouse needed to keep water wet
Tuesday, April 6, 2010 - 18:14
in Astronomy & Space
Four billion years ago, our then stripling sun radiated only 70 to 75 percent as much energy as it does today. Other things on Earth being equal, with so little energy reaching the planet's surface, all water on the planet should been have frozen. But ancient rocks hold ample evidence that the early Earth was awash in liquid water -- a planetary ocean of it.