Jupiter and its four largest moons.
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More and more Moons of Jupiter
News story originally written on March 20, 2003

Astronomers have discovered a dozen new moons of Jupiter so far in 2003. Scott Sheppard and David Jewitt of the University of Hawaii and Jan Kleyna of Cambridge University led the team of astronomers who discovered the new moons. Jupiter now has a total of 52 known moons. All of the new moons are very small, ranging between one and four kilometers in diameter. They all orbit Jupiter in the direction opposite Jupiter's rotation; such orbits are called retrograde.

The moons were discovered using telescopes on the top of the volcano Mauna Kea in Hawaii. For now, the moons all have temporary names. They are called S/2003 J1 through S/2003 J12 ("S" for satellite; "2003" for the year they were discovered; "J" means they are moons of Jupiter; and the 1 through 12 at the end indicates the order each was discovered). Later the moons will be given "real" names. Astronomers think there may be as many as 100 moons with a diameter of one kilometer or greater orbiting Jupiter! Jupiter, the largest planet in our Solar System, has more known moons than any other planet.


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