Astronomy Picture of the Day . Earth Nears Asteroid Toutatis . ... In Earth's sky, Toutatis appeared only as a faint object moving against a background of stars. ... Black Hole Signature From Advective Disks . ... If alone, a black hole would indeed appear quite black, but many black hole candidates are part of binary star systems. So how does a black hole binary system look different from a neutron star binary system? ... Mercury in Stereo: Craters Within Craters . ...