What do you guys think about Pluto? Should it be considered a dwarf
planet?

outofthisworldl...@gmail.com> wrote:
What do you guys think about Pluto? Should it be considered a dwarf
planet?

Out of sight, out of mind. I hardly ever think about Pluto.

Davoud

--
usenet *at* davidillig dawt com

What do you guys think about Pluto? Should it be considered a dwarf
planet?

On 7 Feb 2007 14:26:38 -0800, "outofthisworldlizi"
outofthisworldlizi@gmail.com> wrote:

What do you guys think about Pluto? Should it be considered a dwarf
planet?

For the moment, why not? It's a planet of the dwarf class, just as Mars
is a planet of the terrestrial class and Jupiter is a planet of the gas
giant class. We need to classify the planets as part of the process of
understanding their origins.

"Dwarf planet", however, is a bit weak. I expect a better classification
will be developed that defines it by something a little more important
than size. This particular classification wasn't very well thought out.

What do you guys think about Pluto? Should it be considered a dwarf
planet?

On 7 Feb 2007 14:26:38 -0800, "outofthisworldlizi"
outofthisworldlizi@gmail.com> wrote:

What do you guys think about Pluto? Should it be considered a dwarf
planet?

For the moment, why not? It's a planet of the dwarf class, just as Mars
is a planet of the terrestrial class and Jupiter is a planet of the gas
giant class. We need to classify the planets as part of the process of
understanding their origins.

"Dwarf planet", however, is a bit weak. I expect a better classification
will be developed that defines it by something a little more important
than size. This particular classification wasn't very well thought out.

On Feb 7, 5:15 pm, Davoud <s...@sky.net> wrote:
outofthisworldl...@gmail.com> wrote:
What do you guys think about Pluto? Should it be considered a dwarf
planet?

Out of sight, out of mind. I hardly ever think about Pluto.

Davoud

--
usenet *at* davidillig dawt com

Hmmm...I think about the li'l guy all the time. ;-)

As for the original poster's question?

It's a matter of semantics, but it's clear Pluto is unlike the major
planets, is small, and has an eccentric orbit, relatively speaking.

"Dwarf planet" works for me.

Of course size wasn't the criterion applied to define this new class,
even though the term implies it. Recall that the primary criterion is
the dynamical condition that a planet dominate it's orbit in such a way
that the vast majority of smaller bodies have been removed...

But I feel the science that ultimately lies behind this
distinction is sound.

I have been an astronomer since I was 8 years old, and have never thought
Pluto to be a planet.
It is so different from the rest of the guys that it just can't be.

RMOLLISE wrote:
On Feb 7, 5:15 pm, Davoud <s...@sky.net> wrote:
outofthisworldl...@gmail.com> wrote:
What do you guys think about Pluto? Should it be considered a dwarf
planet?

Out of sight, out of mind. I hardly ever think about Pluto.

Davoud

--
usenet *at* davidillig dawt com

Hmmm...I think about the li'l guy all the time. ;-)

As for the original poster's question?

It's a matter of semantics, but it's clear Pluto is unlike the major
planets, is small, and has an eccentric orbit, relatively speaking.

"Dwarf planet" works for me.

Well, how do you make the cutoff between planet and dwarf planet?

By diameter (from NASA), Mercury (which we say is a planet because we
can see it with the naked eye) is 4879 km. The Moon (which of course
isn't considered a planet, but is here for comparison) is 3475 km. Eris
is (roughly) 2400 km (Hubble measurement), Pluto is 2390 km. Not a lot
of difference.

--
Pat O'Connell
[note munged EMail address]
Take nothing but pictures, Leave nothing but footprints,
Kill nothing but vandals...- Hide quoted text -

- Show quoted text -

On Wed, 07 Feb 2007 17:24:13 -0700, Greg Crinklaw
theskyhoundyoureye@yahoo.com> wrote:

Of course size wasn't the criterion applied to define this new class,
even though the term implies it. Recall that the primary criterion is
the dynamical condition that a planet dominate it's orbit in such a way
that the vast majority of smaller bodies have been removed...

Yes. But IMO a dynamical definition isn't the most useful. Of course, I
don't accept the IAU notion that "planet" should be defined (or if
defined, it should simply be anything orbiting a star, from dust to gas
giants).

In fact, planets need multiple classifications. I think the most
important is generally one related to origin (in the case of Pluto,
probably similar to KBOs). But dynamical classifications can be applied,
too. A single classification strikes me as simplistic- kind of like
limiting all of geology to igneous, metamorphic, and sedimentary.

But I feel the science that ultimately lies behind this
distinction is sound.

I don't. In fact, I don't think there really is much "science" behind
it.

I think you are expecting too much. At this time there can be no real
scientific taxonomy, that's part of the problem.

Yet we seem to need
some distinction between the major and minor bodies, or we'd end up with
hundreds and maybe even thousands of planets in a world where people
want the term "planet" to mean something more restricted. I understand
that this desire/need has nothing at all to do with science, yet it is
necessary nonetheless.

On Wed, 07 Feb 2007 18:29:40 -0700, Greg Crinklaw
theskyhoundyoureye@yahoo.com> wrote:

I think you are expecting too much. At this time there can be no real
scientific taxonomy, that's part of the problem.

We already have a solid taxonomy. And I expect it will get better as we
learn more.

Yet we seem to need
some distinction between the major and minor bodies, or we'd end up with
hundreds and maybe even thousands of planets in a world where people
want the term "planet" to mean something more restricted. I understand
that this desire/need has nothing at all to do with science, yet it is
necessary nonetheless.

We've already got it. In common discourse, planets are Mercury through
Pluto, and (apparently) similar bodies orbiting other stars. For
scientists, every natural orbiting body is a planet, and it's the
classification that matters. I can't imagine any scientist worrying
about whether a body is a "planet"!

Oh come on. You can't seriously be claiming that there is no need for a
definition of planet?