Pluto and Charon
The International Astronomical Union has voted to remove Pluto from the solar system--as a planet, that is.
Meeting in Prague over the past week, IAU members rejected a proposal to increase the number of planets to 12 by including Ceres, the largest known asteroid, which orbits between Mars and Jupiter; Charon, which has been considered Pluto's moon; and 2003 UB313, an object nicknamed "Xena" that was discovered in 2005 orbiting far beyond Pluto.
Pluto is now considered a "dwarf planet" because it has an oblong orbit that overlaps with Neptune's orbit.
Ceres and Xena will also be considered dwarf planets. Charon is simply one of the "small solar system bodies."
Here are images from the Hubble Space Telescope in February that confirmed the existence of two new moons orbiting Pluto. Pluto and Charon are gravitationally locked so the same sides always face each other. They orbit each other every 6.3 Earth days.
August 24, 2006 6:59 AM PDT
Photo by: NASA, ESA, H. Weaver (JHU/APL), A. Stern (SwRI), and the HST Pluto Companion Search Team
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