Pluto moon: The tiny new moon — announced July 20 and called P4 for now — brings the number of known Pluto satellites to four.
NASA, ESA, and M. Showalter (SETI institute) / AP
The tiny new moon — announced July 20 and called P4 for now — brings the number of known Pluto satellites to four. And the find, made with the Hubble Space Telescope, suggests that NASA's New Horizons probe could make some big discoveries, too, when it makes a close flyby of Pluto in 2015, researchers said.
"The discovery of P4 just reinforces what we knew before: This is going to be completely new territory," said Hal Weaver, New Horizons project scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md. "We can't wait." [Pluto: A Dwarf Planet Oddity]
A long journey
The New Horizons spacecraft launched in January 2006 on a mission to study the faraway Pluto system, which has never been visited by a probe. That system is now known to harbor at least four moons: Charon, Nix, Hydra and P4.
When New Horizons' work at Pluto is done, scientists hope the spacecraft can investigate one or two other objects that — like Pluto — are in the Kuiper Belt, a ring of icy bodies orbiting far from the sun.