The powerful space telescope has helped solve many celestial mysteries.
They named it after American astronomer Edwin Hubble, who confirmed the theory of an expanding universe, and the Hubble Space Telescope -- "the Hubble" as it is known to countless admirers -- has done him proud.
Monday, the Hubble marked its 15th anniversary in orbit, a remarkable period in which it has helped fix the age of the universe (at 13.7 billion years), confirmed the presence of black holes in the middle of galaxies, discovered dust disks that lead to the formation of planets around young stars, taken snapshots of the universe shortly after it was formed in the Big Bang, determined the atmospheric composition of a planet orbiting another star and made crucial contributions to the study of the "dark energy" responsible for accelerating the universe's expansion.
Its scientific findings and images -- of stars, planets, nebulae, galaxies, quasars, brown dwarfs, supernovae and other cosmic exotica -- have astounded astronomers and amateur stargazers alike. More than 4,000 scientific papers have been produced from Hubble research, making the telescope one of the most important scientific instruments ever built.
On Monday, NASA released new views of two of the most well-known objects Hubble has ever observed: the Eagle Nebula and the Whirlpool Galaxy (spiral galaxy M51). These new images are among the largest and sharpest Hubble has ever taken.
Launched from the space shuttle Discovery on April 24, 1990, Hubble orbits the Earth at an altitude of 353 miles. It weighs 24,500 pounds and stands 43.5 feet tall -- about the size of a large school bus.
After maintaining the telescope and upgrading it periodically since its launch, NASA in 2004 canceled Hubble's fifth shuttle servicing mission. The decision is being reviewed, but if it stands, the telescope's gyros or batteries will give out sometime after 2007, and Hubble will shut down.