<human>:  Why is the Hubble Space Telescope called Hubble?
<bot>: The Hubble Space Telescope is named after Edwin Hubble. Edwin Hubble was an American astronomer who discovered that the universe is expanding. He is best known for his work in the 1920s and 1930s, when he discovered that the Milky Way galaxy is moving away from other galaxies. He also found that the universe is expanding, and that it is composed of billions of galaxies.