Our solar system would have 12 planets instead of nine under a proposed 'Big Bang' expansion by leading astronomers, changing what billions of schoolchildren are taught about their corner of the cosmos.
The much-maligned Pluto would remain a planet — and its largest moon plus two other heavenly bodies would join Earth's neighbourhood — under a draft resolution to be formally presented on Wednesday to the International Astronomical Union, the arbiter of what is and is not a planet.
"Yes, Virginia, Pluto is a planet," quipped Richard Binzel, a professor of planetary science at the Massachusetts Institute of Technology (MIT). The proposal could change, however: Binzel and the other nearly 2,500 astronomers from 75 nations meeting in Prague to hammer out a universal definition of a planet will hold two brainstorming sessions before they vote on the resolution next week.
Besides reaffirming Pluto's status — whose detractors insist it should not be a planet at all — the new lineup would include 2003 UB313, the farthest-known object in the solar system and nicknamed Xena; Pluto's largest moon, Charon; and the asteroid Ceres, which was a planet in the 1800s before it was demoted.
'Minor planets'— the collective description of asteroids, comets and other non-planetary objects would then be known as 'small solar system bodies'.