The HST has already inspected more than 25,000 astronomical targets (http://hubble.nasa.gov/overview/). Many of these targets have either proved theories or shaped brand new discoveries about space.
One view tested by the HST was the distance between objects in space. Whether they are between stars or planets, distances in space can be deceptive and have only been estimates before (Macchetto, p. 129). In 1929, Edwin Hubble discovered that galaxies get redder, because they are moving away from or Milky Way Galaxy. Hubble's Constant is the term used to describe the distance scale of the universe (Smith, pp. 28-34). In May 1999 a Hubble project team finally decided on the correct Hubble's Constant after measuring distances between different galaxies. They arrived at a figure of seventy kilometer per second per megaparsec (http://hubble.stsci.edu/discoveries/10th/our_universe/in-depth/science.shtml/). This is much less than Hubble's original determined constant (Smith, pp. 28-34). The final determination of this constant would been impossible without the HST's resolution and depth. This project will have a great deal of importance if the space program was to send space crafts deeper into unexplored space.
An unexpected and extraordinary use of the HST was to photograph pictures of the Shoemaker-Levy 9 Comet as it smashed into Jupiter in July 1994 (Ibid.). The twenty-one collisions with Jupiter produced large plumes of dust and debris, which could be seen perfectly with the Telescope. It also tracked the subsequent dust clouds from the impact areas (http://hubble.stsci.edu/discoveries/10th/our_universe/in-depth/science.shtml). The largest of these impacts created a crater as big as the Earth (http://hubble.stsci.edu/discoveries/10th/our_universe/in-depth/planet.shtml)! The images of the Comet hitting Jupiter were probably the most beneficial HST produced images as far as public support goes.