- It is already known that the body was discovered in 2003
by the designation 2003 ULB313.
- Why is it now stated it was spotted in "January",
inferring that the discovery occurs in 2005?
- Even more interestingly, why was the discovery kept secret?
- Note the following statement: "Xena was first spotted
in January. Since then scientists have been checking its position and size
before making their announcement. They had hoped to hold back for longer,
but a secure website containing details of the discovery was recently hacked
and the hacker threatened to release the information."
- The Little Rock Causing Galactic Storm
- It's been named after the warrior princess. But
the only fighting involved with Xena is between scientists, bitterly divided
as to whether she is our latest planet, or just a jumped-up asteroid...
- By Robin McKie
The Observer - UK
- Astronomers have found a new world orbiting the Sun.
The giant lump of rock and ice is larger than the planet Pluto and is now
the farthest known object in the solar system.
- The discovery was announced by US scientists yesterday
and the object has unofficially been named Xena, after the TV series starring
Lucy Lawless. 'We have always wanted to name something Xena,' said Michael
Brown, a member of the team that made the discovery using telescopes at
the Palomar Observatory, outside San Diego, California.
- Preliminary observations suggest Xena - officially known
as 2003 UB313 - is an extremely strange world. It is currently 9 billion
miles away from the Sun, roughly 100 times more distant than the Earth,
and is now about three times more remote than Pluto. At its present distance,
the Sun will appear so small in the sky it will almost be indistinguishable
from other stars.
- Xena will also be incredibly cold. Its surface temperature
is likely to be only a few degrees above absolute zero, while a year there
- the time Xena takes to make one passage round the Sun on its highly elliptical
orbit - will be the equivalent of 560 Earth years.
- Despite its distance, the little world is also proving
to be highly controversial. Astronomers cannot agree whether it is a planet
or just a jumped-up asteroid. Its discoverers are claiming Xena is the
10th planet. Other astronomers say it is just another of the Sun's minor
planets. There are thousands of minor planets in the solar system, but
only nine fully fledged major planets.
- The last full planet to be discovered - in 1930 by US
astronomer Clyde Tombaugh - was Pluto. But recently some astronomers have
campaigned to have Pluto downgraded to 'minor planet' status. It is so
small - its diameter is a mere 2,200 kilometres - that it is unworthy of
the status of full planet, it was argued. This bid was finally rejected
after heated scientific debate.
- But now the discovery of Xena, which is only slightly
bigger than Pluto, will re-ignite that row. Both Pluto and Xena are components
of the Kuiper Belt, which is made up of thousands of small asteroid-like
objects, many mere lumps of rock, that sweep the outermost depths of the
solar system. As members of the Kuiper Belt, neither Pluto nor Xena should
be rated full-fledged planets, it is argued.
- The trouble for astronomers is that they do not have
an exact definition of a planet. Many say that, if Pluto had been discovered
today, it would not have been called a proper planet. In 1999 one group
from the US Minor Planet Centre proposed that Pluto be given a new joint
classification so that it would keep its position among the major planets,
but also be given a designation as a minor planet. The centre dropped the
proposal after outcry from those who saw it as a demotion.
- Gareth Williams of the centre said he still supported
dual status for Pluto, but did not think Xena should be added to the registry
of major planets. It should be left as as a minor planet 'permanently',
- But Mark Sykes, director of the Planetary Sciences Institute
in Tucson, Arizona, disagreed. It should be classed as a full planet, he
said. 'The kinds of questions we would ask about this object [Xena] would
be planet-like questions,' he said. For example, does it have an atmosphere
and what sort of geological processes generated its apparently bright surface?
- This view was backed by the leader of the team that discovered
Xena. 'It is definitely bigger than Pluto, and I would say it counts out
as the 10th planet,' said Brown.
- Xena was first spotted in January. Since then scientists
have been checking its position and size before making their announcement.
- They had hoped to hold back for longer, but a secure
website containing details of the discovery was recently hacked and the
hacker threatened to release the information.
- For Brown, the discovery is particularly satisfying.
Five and a half years ago, he bet fellow astronomer Sabine Airieau five
bottles of good champagne that he would find a Kuiper Belt object larger
than Pluto by the end of last year. In December, having failed, he bought
the champagne to send to her. Then 2003 UB313 was spotted on 8 January.
- 'I lost the bet by eight days,' Brown said. 'But she
graciously decided she would let that window slide and I would win the
bet. That means I get to drink 10 bottles of good champagne. And I think
- Astronomers Detect '10th Planet'
- By Dr David Whitehouse
BBC news website
- The new planet has a highly inclined orbit
- Astronomers in the United States have announced the discovery
of the 10th planet to orbit our Sun. The largest object found in our Solar
System since Neptune was discovered in 1846, it was first seen in 2003
but has only now been confirmed as a planet.
- Designated 2003 UB313, it is about 3,000km across, a
world of rock and ice and somewhat larger than Pluto.
- Scientists say it is three times as far away as Pluto,
in an orbit at an angle to the orbits of the other planets.
- Astronomers think that at some point in its history,
Neptune likely flung it into its highly-inclined 44-degree orbit.
- It is currently 97 Earth-Sun distances away - more than
twice Pluto's average distance from the Sun. Bigger than Pluto
- Its discoverers are Michael Brown of Caltech, Chad Trujillo
of the Gemini Observatory in Hawaii, and David Rabinowitz of Yale University.
- David Rabinowitz told the BBC News website: "It
has been a remarkable day and a remarkable year. 2003 UB313 is probably
larger than Pluto. It is fainter than Pluto, but three times farther away.
- "Brought to the same distance from the Sun as Pluto,
it would be brighter. So today, the world knows that Pluto is not unique.
There are other Plutos, just farther out in the Solar System where they
are a little harder to find."
- It was picked up using the Samuel Oschin Telescope at
Palomar Observatory and the 8m Gemini North telescope on Mauna Kea.
- Slow Mover
- Chad Trujillo told the BBC News website: "I feel
extremely lucky to be part of a discovery as exciting as this. It's not
every day that you find something Pluto-sized or larger!"
- "The spectra that we took at the Gemini Observatory
are particularly interesting because it shows that the surface of 2003
UB313 is very similar to that of Pluto."
- The object was first observed on 21 October 2003, but
the team did not see it move in the sky until looking at the same area
15 months later on 8 January 2005.
- The researchers say they tried looking for it with the
Spitzer Space Telescope, which is sensitive to heat radiation, but failed
to detect it.
- This gives them an upper limit of its size of 3,000 km,
they say. The lower limit still makes it larger than Pluto.
- The discovery of 2003 UB313 comes just after the announcement
of the finding of 2003 EL61, which appears to be a little smaller than