Through chemistry, each bead tells a story, a story of bombardment on both the moon and the Earth at different points in geological history. Despite the repeated meteorite attacks, of course, life eventually did succeed on Earth. Starting about four billion years ago, meteor and asteroid assaults on our planet started to diminish in frequency. Single-celled life forms took hold and began to thrive. We are beginning to suspect that life happens easily, he says.
Life is robust, determined and aggressive.
And if that s true, go outside and stand there on a starry night and wave to your neighbors. Because the chances are very good that there are many other places in the universe where life forms exist. At one point in history, Delano says, Mars was warm, wet and geologically active, and it had a thick atmosphere. Now it s none of those things. Because it s a small planet, it cooled off early and couldn t hold onto its atmosphere.