Posted on 07/29/2005 3:35:26 PM PDT by Right Wing Professor
Add a 10th planet to the solar system - or possibly subtract one.
Astronomers announced today that they have found a lump of rock and ice that is larger than Pluto and the farthest known object in the solar system. The discovery will likely rekindle debate over the definition of "planet" and whether Pluto should still be regarded as one.
The new object - as yet unnamed - is currently 9 billion miles away from the Sun, or about three times Pluto's current distance from the Sun. But its 560-year orbit also brings it as close as 3.3 billion miles. Pluto's elliptical orbit ranges between 2.7 billion and 4.6 billion miles.
The astronomers do not have an exact size for the new planet, but its brightness and distance tell them that it is at least as large as Pluto.
"It is guaranteed bigger than Pluto," said Michael E. Brown, a professor of planetary astronomy at Caltech, who led the team that made the discovery. "Even if it were 100 percent reflective, it would be larger than Pluto. It can't be more than 100 percent reflective."
The discovery was made Jan. 8 using a 48-inch telescope at Palomar Observatory. The astronomers, however, were not able to see it using NASA's Spitzer Space Telescope, which looks at infrared light. That means the planet is less than 1,800 miles in diameter.
(Excerpt) Read more at nytimes.com ...
I thought her heart was still in Hanoi...perhaps that is just wishfull thinking.
I thought her heart was still in Hanoi...perhaps that is just wishfull thinking.
How about 'Ostomy'..its not to far from where Uranus used to be
How about 'Ostomy'..its not to far from where Uranus used to be
This time I won with 15.
Jadis, as in Queen Jadis.
Parmina sounds nice. Does her mom have a name? Hillary, perhaps?
International Astronomical Union
http://www.iau.org/TRANS-NEPTUNIAN_OBJECT_2003_UB.324.0.html
The IAU will publish beginning of September 2006 the definition of a "Planet".
PlutoPluto and Charon are also unique in that not only does Charon rotate synchronously but Pluto does, too: they both keep the same face toward one another. (This makes the phases of Charon as seen from Pluto very interesting.)
Nine Planets
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"To Pluto And Far Beyond" By David H. Levy, Parade, January 15, 2006 -- We don't have a dictionary definition yet that includes all the contingencies. In the wake of the new discovery, however, the International Astronomical Union has set up a group to develop a workable definition of planet. For our part, in consultation with several experienced planetary astronomers, Parade offers this definition: A planet is a body large enough that, when it formed, it condensed under its own gravity to be shaped like a sphere. It orbits a star directly and is not a moon of another planet. |
What Is a Planet?Abstract: A planet is an end product of disk accretion around a primary star or substar. I quantify this definition by the degree to which a body dominates the other masses that share its orbital zone. Theoretical and observational measures of dynamical dominance reveal gaps of 4-5 orders of magnitude separating the eight planets of our solar system from the populations of asteroids and comets. The proposed definition dispenses with upper and lower mass limits for a planet. It reflects the tendency of disk evolution in a mature system to produce a small number of relatively large bodies (planets) in nonintersecting or resonant orbits, which prevents collisions between them.
Steven Soter
The Astronomical Journal,
Volume 132, Issue 6, pp. 2513-2519
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-PJ
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