47 Ursae Majoris system. Artwork of the view from a volcanic Io-like moon of the outer planet of the 47 Ursae Majoris (47 UMa) system. 47 UMa (yellow, upper left) is a nearby Sun-like star. Its planets would orbit between Mars and Jupiter if placed in our solar system. 47 UMa c (centre right) is shown as a ringed Jupiter-like planet. It was discovered in 2001 and has a mass of 0.75 Jupiters. 47 UMa b (upper left, detected in 1995) has a mass of 2.5 Jupiters, and the planets' mass ratio is similar to that of Jupiter and Saturn. Unlike most such planets found, these have circular orbits outside their star's habitable zone. This habitable zone has an imagined water world (blue, upper left).