Although it never ventures beyond low-Earth orbit, Hubble's location high above the blurring effects of the atmosphere gives it an unrivaled vantage point for investigating phenomena throughout the cosmos:
Comet crash: In 1994 Hubble witnessed a rare solar system cataclysm—a series of comet strikes on Jupiter, which produced Earth-sized plumes of vaporized debris in the giant planet's atmosphere.
Star birth: Thanks to its incomparable resolution, Hubble has brought previously hidden stellar processes to light. Perhaps its most famous image shows a dramatic hotbed of new star creation in the Eagle Nebula.
Warped space: Exploiting Einstein's general theory of relativity, Hubble has used the space-warping properties of giant conglomerations of matter, such as galaxy clusters, to detect dark matter and far distant galaxies.
Deep time: In 2003–2004 Hubble trained its instruments on a tiny, seemingly blank spot of sky for a total of 268 hours, recording thousands of distant galaxies in the deepest optical view ever made of the early universe.
These and more than half-a-million other images reveal never-before-seen features of planets, stars, and galaxies with breathtaking clarity that sets Hubble apart from all other telescopes. Now is a good time to assess Hubble's accomplishments, as it enters the third decade of its operational life, by studying a carefully chosen sample of its landmark images in a visual feast that includes many of the greatest discoveries in astronomy during the 1990s and 2000s.