Scientists Discover 10th Planet's Moon

[jpak]

http://www.lasvegassun.com/sunbin/stories/tech/2005/oct/01/100108452.html

LOS ANGELES (AP) - The astronomers who claim to have discovered the 10th planet in the solar system have another intriguing announcement: It has a moon.

While observing the new, so-called planet from Hawaii last month, a team of astronomers led by Michael Brown of the California Institute of Technology spotted a faint object trailing next to it. Because it was moving, astronomers ruled it was a moon and not a background star, which is stationary.

The moon discovery is important because it can help scientists determine the new planet's mass. In July, Brown announced the discovery of an icy, rocky object larger than Pluto in the Kuiper Belt, a disc of icy bodies beyond Neptune. Brown labeled the object a planet and nicknamed it Xena after the lead character in the former TV series "Xena: Warrior Princess." The moon was nicknamed Gabrielle, after Xena's faithful traveling sidekick.

By determining the moon's distance and orbit around Xena, scientists can calculate how heavy Xena is. For example, the faster a moon goes around a planet, the more massive a planet is.

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