This week the Vatican’s Pontifical Academy of Sciences is holding its first major conference on astrobiology, the new science that seeks to find life elsewhere in the cosmos and to understand how it began on Earth. Convened on private Vatican grounds in the elegant Casina Pio IV, formerly the pope’s villa, the unlikely gathering of prominent scientists and religious leaders shows that some of the most tradition-bound faiths are seriously contemplating the possibility that life exists in myriad forms beyond this planet. Astrobiology has arrived, and religious and social institutions — even the Vatican — are taking note.