[FoRK] KBO update -- this one about the size of Pluto,
and much further out
Joseph S. Barrera III
joe at barrera.org
Sun Mar 14 18:54:32 PST 2004
"The importance of Sedna is that it is the first such world discovered
in its normal orbit. Other similar though smaller worlds, like Quaoar
and Varuna, originated in the [Kuiper Belt] but have since been
perturbed into different orbits."
Astronomers discover 'new planet'
By Dr David Whitehouse
BBC News Online science editor
*Astronomers have discovered a new world circling the Sun farther away
than other planets.*
Found in an outer Solar System survey by the recently launched Spitzer
Space Telescope, it has been called Sedna after the Inuit goddess of the
Observations show it is about 2,000 km across, and it may even be larger
than Pluto which is 2,250 km across.
The Hubble Space Telescope has also seen it. Details will be announced
by the US space agency Nasa on Monday.
*World of rock and ice*
Sedna is the largest object found circling the Sun since the discovery
of Pluto in 1930. Its size is uncertain.
One astronomer told BBC News Online that it may even be larger than
It was found during the course of a survey led by Dr Michael Brown of
the California Institute of Technology. Scientists are only midway
through this three-year project.
KUIPER BELT OBJECTS
Icy planetary bodies that orbit beyond Neptune in the distant region
of the Solar System
More than 400 such objects are currently known
They are believed to be remnants of the formation of the Solar
System and among the most primitive objects available for study
Preliminary calculations suggest that it is 10bn kilometres from Earth
in a region of space known as the Kuiper Belt (KB).
The KB contains hundreds of known objects and astronomers believe there
are many more awaiting discovery. Most are small worlds of rock and ice
but some, like Sedna, could be as large as or larger than Pluto.
The importance of Sedna is that it is the first such world discovered in
its normal orbit. Other similar though smaller worlds, like Quaoar and
Varuna, originated in the KB but have since been perturbed into
Following the objects discovery astronomers at the Tenagra Observatory
in Arizona were asked to provide positional information so that an orbit
could be determined for Sedna.
The new discovery will reignite the debate about what is a planet.
One group of astronomers believe that Pluto is not a true planet but
merely one of the largest of a vast number of minor objects in the outer
The alternative standpoint is that Pluto is a planet and those who
believe that will have to classify Sedna as the tenth planet.
Story from BBC NEWS:
Published: 2004/03/15 01:12:07 GMT
© BBC MMIV
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