... Tonight's Sky . ... Supernova showered Earth with radioactive debris . ... Herschel finds oceans of water in disk of nearby star . ... Using data from the Herschel Space Observatory, astronomers have detected for the first time cold water vapor enveloping a dusty disk around a young star. The findings indicate that this disk, which is poised to develop into a solar system, contains great quantities of water, suggesting that water-covered planets like Earth may be common in the universe. ...