January 4, 2013
Maybe the Early Earth Wasn't a Snowball
Emily Elert, Popular Science
When our sun first got going, some 4.5 billion years ago, it wasn't the same blazing star we know today--its warmth and brightness grew gradually as more and more of its fuel ignited. So, for Earth's first two billion years, our planet was bathed in a light 25 percent dimmer than it receives today.
TAGGED: Early Earth, Snowball Earth, Atmosphere