What Major discoveries did the hubble telescope find?

Many, many, many. Just a few include: Information about planets around other stars. Detailed observations of the Shoemaker-Levi comet crash into Jupiter, giving information about comets and Jupiter. Detailed distances to far away galaxies, allowing refinement of the speed that the universe expands, leading to the discovery of dark energy. Detailed observations of gravitational lensing, leading to dark matter. Discovery that ancient galaxies are different and more irregularly shaped than current galaxies.