The latest on Pluto - officially stripped of planetary status

[Omaroo (Chris Malikoff)]

http://www.news.com.au/story/0,23599,20246532-2,00.html

And then there were eight...

By Alan Crosby in Prague
August 25, 2006 03:00am

Article from: Reuters


PLUTO was stripped of its status as a planet overnight when scientists from around the world redefined it as a "dwarf planet", leaving just eight classical planets in the solar system.

With one vote, toys and models of the solar system became instantly obsolete, forcing teachers and publishers to scramble to update textbooks and lessons used in classrooms for decades.

“Pluto is dead,” Mike Brown of the California Institute of Technology bluntly said on a teleconference. Discovered in 1930 by the American Clyde Tombaugh, Pluto has traditionally been considered the ninth planet, farthest from the sun in the solar system.

However, the definition of a planet approved after a heated debate among 2500 scientists from the International Astronomical Union (IAU) meeting in Prague drew a clear distinction between Pluto and the other eight planets.
The need to define what is a planet was driven by technological advances enabling astronomers to look farther into space and to measure more precisely the size of celestial bodies.

Mr Brown added impetus to the decades-old debate on the definition of a planet when he discovered UB313 in 2003. Xena, as it is nicknamed, is larger than Pluto, instantly creating a buzz over whether a new planet had been discovered.

The scientists agreed that, to be called a planet, a celestial body must be in orbit around a star while not itself being a star.

It must be large enough in mass for its own gravity to pull it into a nearly spherical shape and have cleared the neighbourhood around its orbit.
Pluto was disqualified because its oblong orbit overlaps with Neptune's. Xena also does not make the grade of being a planet, and will also be known as a dwarf planet.

“It's an issue mainly for the public, not really for scientists. Some people may be upset, but we've long regarded it (Pluto) as a minor planet,” said Richard Miller of the University of Chicago.

The new definition - the first time the IAU has tried to define scientifically what a planet is - means a second category called “dwarf planets”, has been created, as well as a third category for all other objects, except satellites, known as small solar system bodies.

”We are just defining a new class of planets and I think it's very appropriate. We are finding more planets in our solar system, and some are larger than Pluto,” said Philip Diamond, a professor at the University of Manchester and a delegate attending the IAU meeting.

“I think what we have done is a good thing, we have actually expanded the number of planets in our solar system, but just spread them over two categories.”

From now on, traditional planets will be restricted to eight: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

Meanwhile, the widow of Clyde Tombaugh said he would have understood why his discovery was demoted to non-planet status because he was a good scientist.

“Clyde said, 'Well, it's there. You can do what you want with it',” Patricia Tombaugh, 94, said from her home in Las Cruces, New Mexico. Her husband, who discovered Pluto while working at the Lowell Observatory in Arizona, was disappointed and frustrated when scientists began questioning its status.

But, she said: “Clyde would have said, 'Science is a progressive thing and if you're going to be a scientist and put your neck out, you're apt to have it bitten upon'.”

Mrs Tombaugh said a tiny amount of her husband's ashes were on a spacecraft bound for Pluto.

[iceman (Mike)]

Thanks for the post Omaroo.

It's already being discussed in this post, so you may want to add your thoughts there.

I'll lock this thread to avoid confusion.