LOS ANGELES, July 30: A US astronomer said on Friday he had discovered a 10th planet in the outer reaches of the solar system that could force a redrawing the astronomical map. If confirmed, the discovery by Mike Brown of the California Institute of Technology would be the first of a planet since Pluto was identified in 1930, shattering the notion of a nine-planet solar system.
“Get out your pens. Start rewriting textbooks today,” said Mr Brown, a professor of planetary astronomy, announcing what he called ‘the 10th planet of the solar system’, one that is larger than Pluto. “It’s the farthest object ever discovered to orbit around the sun,” Mr Brown said in a conference call of the planet that is covered in methane ice and lies nearly 15 billion kilometres from Earth.
“I’d say it’s probably one-and-a-half times the size of Pluto,” he said from CalTech, based in Pasedena, near Los Angeles, referring to what until now has been the most distant planet in the solar system.
Currently about 97 times further from the Sun than the Earth, the celestial body, tentatively called ‘2003-UB313’, is the farthest known object in the solar system, and the third brightest of the Kuiper belt objects.
It is a typical member of the Kuiper belt, but its sheer size in relation to the nine known planets means that it can only be classified as a planet, Mr Brown said.
The astronomer conceded he and his team did not know the exact size of the new planet, but its brightness and distance tell them that it is at least as large as Pluto, which measures 2,302 kilometres in diameter.
The size of an object in the solar system can be inferred by its brightness, just as the size of a faraway light bulb can be calculated if one knows its wattage, he explained.
“We are 100 per cent confident that this is the first object bigger than Pluto ever found in the outer solar system.”
But Mr Brown conceded that the discovery would likely rekindle debate over the definition of the term ‘planet’ and whether Pluto should still be regarded as one.
Mr Brown discovered what could be an addition to the universe known to man along with colleagues Chad Trujillo, of the Gemini Observatory in Mauna Kea, Hawaii, and David Rabinowitz, of Yale University, on Jan 8.
The planet was first spotted on Oct 31, 2003, with the Samuel Oschin Telescope at Palomar Observatory near San Diego, California.
But it was so far away that its motion was not detected until the scientists reanalysed the data earlier this year, Mr Brown said.
The astronomers have proposed a name for the ‘planet’ to the science’s governing body, the International Astronomical Union, and are awaiting the decision of this body before announcing it.
The planet has not been noticed previously because its orbit is at a 45 degree angle to the rest of the solar system, he said.
“We found it because we’ve looked everywhere else. Nobody looks way up that high. It’s tilted way out of plane,” he added.
The new planet, which Mr Brown said looks very much like Pluto, will be visible over the next six months and is currently almost directly overhead in the early-morning eastern sky, in the Cetus constellation.—AFP
LOS ANGELES, July 30: A US astronomer said on Friday he had discovered a 10th planet in the outer reaches of the solar system that could force a redrawing the astronomical map. If confirmed, the discovery by Mike Brown of the California Institute of Technology would be the first of a planet since Pluto was identified in 1930, shattering the notion of a nine-planet solar system.
