[meteorite-list] RE: Pluto may yet lose planet status

From: Steve Schoner <schoner_at_meteoritecentral.com>
Date: Sun Aug 20 04:11:00 2006
Message-ID: <20060819.223347.29818.602909_at_webmail27.nyc.untd.com>

Being that I have a vested interest in this in that I own Clyde
Tombaugh's Flagstaff House

Google "Clyde Tombaugh House"

And that he discovered Pluto, I think that this object should be
considered a planet in so far as it is the closest representative of
K-belt objects.

Are there any others closer?

And do any have moons as large as Pluto has?

Keep things as they are and let history speak.

75 years of acceptance is hard to sweep away, not to mention the
arduous task that Tombaugh had to endure to find this object. I know
as I worked at Lowell Observatory from 1971 to 1974, and was well
acquainted with his technique.

It amazes me that he could endure looking at hundreds of thousands of
stars, perhaps even millions on big photographic plates with a blink
comparator and out of that spot this tiny object.

Then do the calculations by hand to determine how far away it was.

I held the original plate and plate envelope with Tombaugh's
handwriting on it. One can read his excitement at having made the
discovery.

Let history books stand.

Leave Pluto as a planet alone.

Steve Schoner
IMCA 4470

P.S.

My daughter has just moved into the Tombaugh House and is the first to
live in it since I moved it 4 years ago. It is on its way to becoming
a Flagstaff landmark.



  



http://www.newscientistspace.com/article/dn9797-pluto-may-yet-lose-planet-status.html

Pluto may yet lose planet status
Stephen Battersby
New Scientist
18 August 2006

We were about to gain a horde of new planets; now we might lose one
instead.

In Prague, astronomers are trying to define what it means to be a
planet. A draft definition released on Wednesday would have extended the
club from the conventional nine to twelve, and soon to many more (see
Three new planets may join solar system
<http://www.newscientistspace.com/article/dn9761-three-new-planets-may-join-solar-system.html>).

But on Friday, astronomers at the meeting suggested a different scheme -
one that would instead relegate Pluto to the status of "dwarf planet".

Wednesday's original proposal was made by the International Astronomical
Union's official planet definition committee (read the IAU's proposed
definitions of a planet, a pluton and other objects
<http://www.newscientistspace.com/article/dn9762>). Their suggestion was
to include any round object that independently orbits the Sun -
including Ceres (formerly considered an asteroid), Pluto's companion
Charon, and the distant body currently known as Xena.

Largest body

On Friday, another definition, put forward by a group led by Julio
Fernandez of the University of the Republic in Montevideo, Uruguay,
received some support. It includes the clause that a planet also has to
be "by far the largest body in its local population".

So Pluto would be out, because the 2300-kilometre-wide body is similar
in size to many other objects in the same region, the chilly Kuiper Belt
beyond Neptune. There would be only eight planets in the solar system,
unless someone finds another really big one out there somewhere.

Some scientists had qualms about the sheer number of planets in the
original scheme. Many of the icy objects in the Kuiper Belt are probably
round, so we would soon end up with dozens of planets. Eventually there
could be 200, according to Caltech astronomer Mike Brown, who has
discovered several of these objects.

Many would be very small, less than 500 kilometres across. And depending
on how strict the definition of roundness is, the proposed scheme could
even admit tiny bodies such as 2002BM26. This near-Earth asteroid is
nearly round, despite being less than a kilometre across - probably
because it is a loose, weak agglomeration of rubble.

Making a planet of Charon opens up other problems. By Wednesday's
proposal, Charon would be a planet rather than a satellite because the
mutual centre of gravity of Pluto and Charon is out in space between the
two bodies.

Absurd debate

The same could one day be true of our Moon, which is slowly receding
from the Earth - so in a few billion years, the two would become twin
planets. Odder still, we might one day find an object that constantly
switches back and forth from planet to satellite as it moves around a
highly elongated orbit.

The new definition dispenses with those problems by insisting that
planets must be the dominant bodies in their neighbourhoods. The idea
behind it is that real planets form by sweeping up debris in a broad
zone around their orbit. Pluto, Ceres and the rest are merely debris
that were never swept up.

But today's rival proposal could also have snags. For example, what
exactly is meant by "by far the largest"?

At this point, opinion seems to be split over which way to go, and next
week's vote could be close.

"I think the whole debate is absurd," says Richard Conn Henry, an
astronomer at Johns Hopkins University in Maryland, US.

"The fact (in my opinion) that Pluto is in a different class from the
eight planets does not make it less interesting," he told New Scientist.
"It is a fascinating object."
Received on Sun 20 Aug 2006 01:32:52 AM PDT