Pluto leaving Solar System entirely

Image of Pluto captured
by Hubble Space Telescope

An acceleration detected in Pluto's orbital velocity since Aug. 24 will, if maintained, take the dwarf planet and its moons out of the solar system within a decade.

"Was it something we said?" joked one astronomer.

Last Thursday, the International Astronomical Union defined "planet" to mean all of the planets discovered around our star before 1930.

The vote in Prague came as a surprise. A unanimous committee had earlier proposed a simpler definition that was more ... universal.

But then a mysterious female astronomer appeared, urging that newly discovered body UB313 (casually known as Xena) not be considered a planet. Astronomers focused on every word, many via advanced optics.

Mystery astronomer

This is not the first time a celestial body has been demoted from the status of planet. Ceres was originally considered a planet in the early 1800s, but was demoted to "minor planet" in the latter part of that century.

"I understand how Pluto is feeling," said The Asteroid Formerly Known as a Planet.

Despite the demotion and departure of Pluto, astronomers expect to bring the Solar System back to nine planets.

"We're actively seeking the planet resided on by President Bush and his administration," said Caltech astronomer Ed Barnard. "It's obvious they're not living on this one."