Vega has been known to astronomers for centuries. At least, astronomers thought they knew most things about this brilliant blue star. But Vega has been keeping a secret. It is surrounded by a planetary system in the early stages of development. This discovery is the latest in a series of unexpected finds by IRAS, the infra-red astronomical satellite launched in January 1983. Patrick Moore talks to astronomers Dr Aumann and Dr Gillette and discusses the importance of this major contribution to our knowledge of the universe.