The Hubble Space Telescope was launched 25 years ago, on April 24, 1990. Since then it has changed the way we look at the universe.
Hubble has given us clear views of the outer planets in our solar system, views of distant galaxies, star clusters, nebulae and black holes.
As a result astronomy text books have changed to reflect these new discoveries.
See the Hubble 25th Anniversary website for more details.