November 1, 2005If any celestial body in the solar system could use some good news, it's Pluto. For the last 4.6 billion years, it's sat in a cold, dim orbit three billion miles (five billion kilometers) from the sun. As far as we knew, its closest companion was the moon Charon, named for the ferryman of the deadnot exactly warm and fuzzy company.
But yesterday scientists announced that Pluto may have two additional moons. Astronomers spied the candidate satellites, named S/2005 P1 and S/2005 P2, in May using the Hubble Space Telescope. The twin satellites appear to loop around Pluto in a circular orbit.
If confirmed by the International Astronomical Union, the discovery will mark the first time an object in the Kuiper Beltthe huge swath of icy, rocky bodies in the outermost solar systemhas been found to have more than one moon.
"Our result suggests other bodies in the Kuiper Belt may have more than one moon," Alan Stern, a planetary scientist and team co-leader, said in a press statement. "It also means planetary scientists will have to take these new moons into account when modeling the formation of the Pluto system."