Astronomers from the Harvard-Smithsonian Center for Astrophysics have found a diamond in space, and it's big? really big. The object, technically known as BPM 37093, is a crystallized white dwarf star approximately 4,000 km across. The astronomers call it a diamond, because it's made up of crystallized carbon surrounded by a thin layer of hydrogen and helium gasses. It's believed that this is the final outcome for many stars, including our own Sun. In five billion years our Sun will become a white dwarf and two billion years after that the carbon should crystallize to form a gigantic diamond.