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Pluto comes under attack
14/08/2006 10:51 - (SA)
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| An artist's concept of Kuiper Belt object 2003 UB313 (nicknamed "Xena") and its satellite, Gabrielle. The solar system is suffering an identity crisis. For the past 76 years, it consisted of nine planets, even though scientists debated whether Pluto was really part of the club. (Nasa, AP File) |
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Prague - Despite being the farthest planet
from earth in our solar system, Pluto has come under attack from
astronomers and may be about to lose its status in the battle.
About 3 000 astronomers and scientists from around the world
will meet in Prague this week to decide whether Pluto,
discovered in 1930, measures up to the definition of a planet.
In defining for the first time what exactly a planet is, the
International Astronomers Union (IAU) may be forced to downgrade
Pluto's status, or add as many as 14 others.
Such a decision would send shockwaves through the scientific
community, instantly outdate textbooks, and cause educators to
re-teach the basics of our solar system.
"The pivotal question is the status of Pluto, which is
clearly very different from Jupiter, Saturn, Uranus, and
Neptune," Owen Gingerich, professor of Astronomy and History of Science emeritus a the Harvard-Smithsonian Centre for
Astrophysics told Reuters.
Named after TV character
Debate has raged within the scientific community over the
status of Pluto for decades after the planet was found to be
only one four-hundredths of the mass of the earth.
That discussion intensified in 2003 when astronomers at the
California Institute of Technology discovered UB 313. Nicknamed
Xena after the character in the television show, UB 313 is one
of more than a dozen celestial bodies in our solar system found
to be larger than Pluto.
Xena and Pluto are large icy bodies that reside in the
Kuiper Belt - where thousands of floating bodies travel -
beyond Neptune. Images from the Hubble Space Telescope put
Xena's diameter at about 1 490 miles. That is slightly bigger than Pluto, which measures 1 422 miles across.
Gingerich is the chair of a committee that was asked to come
up with a definition of a planet and hand it to the IAU general
assembly, which runs from August. 14-25.
In the run-up to the assembly, emotions have been running
high in both directions.
Some have appealed to Gingerich's group not to downgrade
Pluto, saying it would disappoint children and throw our
understanding of the universe into chaos.
Others say let the chips fall where they may and seem to
relish the idea of overturning our current view of the universe.
Gingerich said that modern technologies have allowed
scientists to delve into the solar system further, and in more
detail, than ever before. Therefore, it is no surprise that
questions on the fundamental assumptions of it are arising.
"Should it (Pluto), for historical reasons, be considered a
planet like the rest?" Gingerich asks, refusing to tip his hand on how the seven-member group has agreed after deciding on the wording in June.
Scientists say the group may make a new class of planets
that accepts large bodies such as Xena and Pluto that do not
measure up to the eight larger planets.
They could also drop Pluto's status as a planet or expand the list of planets to include many similarly-sized bodies found in the solar system.
- Reuters
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