This image shows the center of the globular cluster Messier also known as as observed by the NASA/ESA Hubble Space Telescope. Globular clusters are spherical collections of densely packed stars, relics of the early .
Two black holes are entwined in a gravitational tango in this artist's conception. Supermassive black holes at the hearts of galaxies are thought to form through the merging of smaller, yet still massive black holes, such as the ones depicted here.
See photos and images of Ceres, a dwarf planet and the largest asteroid in the solar system yet known. Ceres is round and may contain more fresh water than the entire Earth. NASA's Dawn spacecraft will explore Ceres in