A crowded Universe
By SUN ONLINE REPORTER
There may soon be more than 9 planets in the Solar System
EARTH'S neighbourhood could soon swell to well beyond 12
planets after the International Astronomical Union proposed enlarging the world’s understanding of the solar system.
The IAU says it has a watchlist of about a dozen potential candidates for planethood.
Most would be known as 'plutons' under a proposed new definition that would distinguish between the nine classical planets - Mercury,
Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune and Pluto, along with objects like it in the far reaches of the solar system beyond Neptune.
"There’s a whole list of candidates knocking at the door," said Owen Gingerich, who chairs the planetary definition committee of the IAU, the body that decides what is and isn’t a planet.
"Don’t get stuck on this number 12, because that won’t last the whole of next year," he said in Prague, where 2,500 of the world’s leading astronomers are considering a new definition for planets.
Under the proposal, which will be voted on next week, Pluto would remain a planet but would be known as a pluton.
Joining it on the list of planets would be three other plutons: Pluto’s largest moon, Charon; 2003 UB313, or Xena, the farthest-known object in the solar system and the asteroid Ceres, which was a planet in the 1800s before it was demoted.
Critics, who include 2003 UB313 discoverer Michael Brown of the California Institute of Technology, contend the new classification would be ungainly and admit objects to the planetary club that don’t belong because of their small size and mass or other factors.
thesun.co.uk
By SUN ONLINE REPORTER
There may soon be more than 9 planets in the Solar System
EARTH'S neighbourhood could soon swell to well beyond 12
planets after the International Astronomical Union proposed enlarging the world’s understanding of the solar system.
The IAU says it has a watchlist of about a dozen potential candidates for planethood.
Most would be known as 'plutons' under a proposed new definition that would distinguish between the nine classical planets - Mercury,
Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune and Pluto, along with objects like it in the far reaches of the solar system beyond Neptune.
"There’s a whole list of candidates knocking at the door," said Owen Gingerich, who chairs the planetary definition committee of the IAU, the body that decides what is and isn’t a planet.
"Don’t get stuck on this number 12, because that won’t last the whole of next year," he said in Prague, where 2,500 of the world’s leading astronomers are considering a new definition for planets.
Under the proposal, which will be voted on next week, Pluto would remain a planet but would be known as a pluton.
Joining it on the list of planets would be three other plutons: Pluto’s largest moon, Charon; 2003 UB313, or Xena, the farthest-known object in the solar system and the asteroid Ceres, which was a planet in the 1800s before it was demoted.
Critics, who include 2003 UB313 discoverer Michael Brown of the California Institute of Technology, contend the new classification would be ungainly and admit objects to the planetary club that don’t belong because of their small size and mass or other factors.
thesun.co.uk
