... Bad Astronomy . ... Bitesize Astronomy . ... The Nine Planets . ... It isn't the first extrasolar planetary system to be discovered; the first planet outside our own solar system orbiting a normal Sunlike star was discovered in 1995. ... Still, this is the first solar system ever found besides our own to definitely have more than one planet. This is an important discovery: most people all along have been assuming that multiple planet systems exist, but we had never actually seen one. ...