Stars of the Coma star cluster shine brightly outside the International Space Station in this shot by astronaut Don Pettit. Astronomers have discovered about 60 members of the cluster, which also is known as Melotte 111, and are still looking for more. The cluster is about 280 light-years away, in the constellation Coma Berenices, but is so spread out that it's difficult to confirm which stars belong to it. [NASA/Donald Pettit]