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The Moons of Pluto - Windows to the Universe

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This picture shows Pluto (left) and its big moon Charon (right). Notice how big Charon is compared to Pluto. Notice how close Charon is to Pluto. This picture was taken by the Hubble Space Telescope in 1994.
Click on image for full size
Image courtesy Dr. R. Albrecht (ESA/ESO Space Telescope European Coordinating Facility) and NASA.

The Moons of Pluto

Pluto has moons. One of the moons is very large. The large moon is named Charon. The other two moons are fairly small. They don't really have names yet. For now they are called S/2005 P1 and S/2005 P2.

Charon is nearly as big as Pluto. Some astronomers call Pluto and Charon a double planet. James Christy discovered Charon in 1978.

S/2005 P1 and S/2005 P2 were discovered in 2005. A team of astronomers led by Alan Stern and Harold Weaver found the moons. The team was looking for new moons of Pluto using the Hubble Space Telescope. They were getting ready for the New Horizons space mission to Pluto. S/2005 P1 is about 150 km (93 miles) across. S/2005 P2 is even smaller, about 100 km (62 miles) across. S/2005 P1 takes 38 days to go around Pluto. S/2005 P2 orbits Pluto every 25 days.

S/2005 P1 and S/2005 P2 will get "real" names after astronomers observe them a few more times. They want to make sure they are moons of Pluto before they give them permanent names.

We don't know whether Pluto has rings or not. Nobody has seen any rings around Pluto so far.

Last modified January 23, 2006 by Randy Russell.

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