This image, taken by NASA's Hubble Space Telescope, shows five moons orbiting the distant, icy dwarf planet Pluto. The green circle marks the unnamed moon, designated P5, as photographed by Hubble's Wide Field Camera 3 on July 7 2012. The unnamed moon P4 was uncovered in Hubble imagery in 2011. Credit: NASA; ESA; M. Showalter, SETI Institute