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. [The planet was] nicknamed… Xena after the lead character in the former TV series “Xena: Warrior Princess.” The moon was nicknamed Gabrielle, after Xena’s faithful traveling sidekick…
The newly discovered moon is about 155 miles wide and 60 times fainter than Xena, the farthest-known object in the solar system. It is currently 9 billion miles away from the sun, or about three times Pluto’s current distance from the sun.
Scientists believe Xena’s moon was formed when Kuiper Belt objects collided with one another. The Earth’s moon formed in a similar way when Earth crashed into an object the size of Mars.
