One Thing Comet Probe Hubbub Has Right: Water Is Vital to Life Chemistry

Editor's Note: We are pleased to present a new series at ENV, "Exoplanets." Daniel Bakken is anengineer who teachesastronomy at the college level, and an entrepreneur in compound semiconductor crystal growth. In a series of articles he will critically examine recent claims about exoplanets beyond our solar system, asking whether our own planet Earth is a rarity, or common, in the cosmos.

With the landing of a European probe yesterday on comet 67P/Churyumov-Gerasimenko, excitement in the media...