(CNN) — Almost exactly one year after discovering dwarf planet Pluto’s fourth moon — though not before actually naming poor little P4 — NASA announced Wednesday, July 11th a fifth moon has been discovered orbiting the ex-planet.
Astronomers using the Hubble Space Telescope found the irregularly shaped moon, which they said measures 6 to 15 miles across. For now, it’s being called P5.
“The moons form a series of neatly nested orbits, a bit like Russian dolls,” said Mark Showalter of the SETI Institute in a statement released by the European Space Agency. Showalter is the leader of the scientific team that discovered the new moon.
The moon was detected in nine separate sets of images taken by Hubble’s Wide Field Camera 3 on June 26, 27 and 29, and July 7 and 9, NASA says.
Pluto’s other moons are Charon, Nix and Hydra.
The team at SETI Institute is “intrigued” that Pluto, deemed unworthy of planethood in 2006, could have “such a complex collection of satellites,” the statement said.
The leading theory is that all the moons are remnants of a collision billions of years ago between Pluto and another large object from the Kuiper Belt — the region of the solar system beyond Neptune.
Because Pluto is so far away from Earth, the images of P5 look like small white dots. But a NASA spacecraft that is on its way to Pluto and will give scientists better images and details about the former planet and its neighbors.
The New Horizons spacecraft was launched in 2006, just months before Pluto was demoted by the International Astronomical Union, and is now about halfway to the icy dwarf planet. It’s due to fly past it in July of 2015.