There is only enough room in this book to mention a very few of the incredible cosmic discoveries that HST has enabled astronomers to make. Using Hubble, astronomers have taken the deepest-ever image of the universe; found the most distant galaxies in the universe (thirteen billion light-years away); measured the cosmic expansion rate; helped confirm the existence of “dark energy” and the accelerating ex-262 pansion of the universe; discovered four tiny new moons orbiting Pluto; located exoplanets orbiting distant stars; and proven that there are supermassive black holes in the vast majority of spiral and elliptical galaxies.