Photos of Pluto and Fourth Moon

Fourth Moon Discovered Around PlutoCredit: NASA, ESA, and M. Showalter (SETI institute)

Two labeled images of the Pluto system, released on July 20, 2011, taken by the Hubble Space Telescope's Wide Field Camera 3 ultraviolet visible instrument with newly discovered fourth moon P4 circled.

The image on the left was taken on June 28, 2011. The image of the right was taken on July 3, 2011.

Illustration of the Pluto satellite system orbits with newly discovered moon P4 highlighted, released July 20, 2011.