Nasa, National Aeronautics and Space Administration: an independent agency of the United States government responsible for aviation and spaceflight celebrates 20th anniversary of hubble telescope today. Age of the universe, The discovery of dark energy, Hubble telescope explores the cosmos since eight years.

          Hubble telescope is  a cornerstone in the understanding of exoplanets. Hubble telescope is part of a whole, but it is true instrumentation including spectroscope has provided us with unique information and nasa is very happy to celebrate 20th anniversary of HUBBLE TELESCOPE.