... Tonight's Sky . ... Observing . ... Extrasolar Earths? More than one-third of the planet systems detected outside our solar system may harbor earthlike planets covered in deep, global oceans. ... M ore than one-third of the giant planet systems detected outside our solar system may harbor Earth-like planets that offer abundant potential for life, according to a new study by two scientists from Penn State and one from the University of Colorado associated with NASA's Astrobiology Institute. ...