Although astronomers have discovered over 130 planets orbiting stars outside our solar system, we've never actually seen any of them. We know about them because of the changes they cause in a star's brightness, or wobbles in a star's orbit, or a number of other inferential methods. But the Hubble space telescope may have captured the first image of a planet outside of our own system -- a gas giant, roughly five times the size of Jupiter, in a distant orbit around a so-called "brown dwarf" star about 225 light years from Earth. The astronomer leading the research, Glenn Schneider of the University of Arizona, says he is "99.1 percent sure" it's a planet; further observations will make it "99.9 percent sure."
A number of features made it possible for this planet to be seen -- its size, distance from its parent star, and the fact that brown dwarf stars are too small to shine like a normal star and wash out the dimmer reflection and heat of a planet.