Extrasolar planet. Artwork of an extrasolar ringed gas giant planet, seen from the icy surface of one of its moons or a passing comet. If seen from a moon, the moon would be in a polar orbit, rather than the more normal equatorial orbit. The shadow of the planet is seen on the ring system. This ring system, like that of Saturn, consists of chunks of rock and ice from a moon torn apart by the planet's strong tidal forces, or prevented from forming by the same forces. Some planets with the mass of gas giants have been discovered orbiting nearby stars.