Photo: NASA; ESA; M. Showalter, SETI Institute
This image, taken by NASA's Hubble Space Telescope, shows five moons orbiting the distant, icy dwarf planet Pluto. The green circle marks the newly discovered moon, designated P5, as photographed by Hubble's Wide Field Camera 3 on July 7.
A far-out fifth moon has been discovered orbiting the distant "dwarf planet" Pluto -- the one-time planet planet demoted by Caltech's Kavali Prize-winning astrophysicist Mike Brown.
With the use of the Hubble telescope, a team of scientists spotted the smallest moon yet around Pluto, NASA announced Wednesday.
The mini-moon, estimated to be 6 to 15 miles across, will be called P5 until a catchier name is decided upon. P5 is even smaller than last year's discovery of moon number four, measured at 8 to 21 miles wide. Charon, Pluto's largest moon, is about 650 miles across.
NASA's New Horizons spacecraft is speeding toward the icy object with a planned flyby in July 2015 (Pluto was still considered a full-fledged planet when the craft launched in 2006).