In the search for extraterrestrial life, scientists have turned over all sorts of rocks. Mars, for example, has geological features that suggest it once had — and still has — subsurface liquid water. Scientists have also eyed Saturn’s moons as well as Jupiter’s as possible havens for life in the oceans under their icy crusts. Now, however, scientists are dusting off an old idea that promises a new vista in the hunt for life beyond Earth: the clouds of Venus.