Timeless photos and the best images of the week, from the Phoenix mission to Mars and of the solar system.
Located 10,000 light-years away in the northern constellation Cassiopeia, Cassiopeia A is the remnant of a once massive star that died in a violent supernova explosion 325 years ago.
It consists of a dead star, called a neutron star, and a surrounding shell of material that was blasted off as the star died.
Everything from 'Walnut Veneer' to 'Virulent Yellow'