The Ur-Quan Masters Discussion Forum

The Ur-Quan Masters Re-Release => Starbase Café => Topic started by: XR4-IT on August 16, 2006, 05:33:59 pm



Title: Plan boosts solar system to 12 planets
Post by: XR4-IT on August 16, 2006, 05:33:59 pm
So the planet debate has heated up again and in fact it looks like we will soon have a new planet definition…

See this http://www.msnbc.msn.com/id/14364833/?GT1=8404

The article describes the new planet definition and gives the names of new planets like Ceres (between Mars and Jupiter) Charon & Pluto as a bi-planet and Xena (2003 UB 313 beyond Pluto)

So what’s your opinions on the “new” planets.


Title: Re: Plan boosts solar system to 12 planets
Post by: Death 999 on August 16, 2006, 06:36:54 pm
http://www.scalzi.com/whatever/004405.html

(warning: video)


Title: Re: Plan boosts solar system to 12 planets
Post by: Lance_Vader on August 16, 2006, 07:11:26 pm
Why Xena?  Why not one of the Roman gods we haven't already used?  I mean, it's not like we're going to run out of 'em or anything...


Title: Re: Plan boosts solar system to 12 planets
Post by: Arne on August 16, 2006, 07:12:14 pm
Wha? Their definition exludes any moons so why include Charon?

I'd say there are 8 planets, if it weren't for the fact that Pluto has a moon, which makes it rather planet like... but then again, Xena does also have a moon, doesn't she? Applying digital definitions on analog stuff is tricky business.


Title: Re: Plan boosts solar system to 12 planets
Post by: XR4-IT on August 16, 2006, 07:42:29 pm
Wha? Their definition exludes any moons so why include Charon?

I think it’s because Charon doesn’t actually orbit Pluto. Pluto and Charon revolve around each other and that is why they are calling it a bi-planet system. 

Oh and Death that video was great.


Title: Re: Plan boosts solar system to 12 planets
Post by: Draxas on August 16, 2006, 08:00:49 pm
I wonder where I can get a stuffed Cthulu from? ;D

See that? Reorganizing the solar system makes children cry, and then want to kill you.


Title: Re: Plan boosts solar system to 12 planets
Post by: Zeep-Eeep on August 16, 2006, 09:50:27 pm
I fail to see the point in debating whether balls of ice and rock millions of miles away
are planets or moons or comets or just random rocks. Seems kinda silly.

Really, if we're going to open this topic, we should ask what the Pultonians think
about the whole mess.


Title: Re: Plan boosts solar system to 12 planets
Post by: Zieman on August 16, 2006, 11:40:53 pm
As a self-proclaimed honorary Pultonian I say: let's play FRUNGY!

And a bit more seriously: because Pluto was given  'planet' status when it was discovered, I think that any rock, dust or ice ball with equal or greater than Pluto's diameter and/or mass should be called 'planet'. :)


Title: Re: Plan boosts solar system to 12 planets
Post by: meep-eep on August 16, 2006, 11:48:36 pm
[...] Xena does also have a moon, doesn't she? Applying digital definitions on analog stuff is tricky business.
Yes, Gabrielle (seriously). Although neither name is "official".



Title: Re: Plan boosts solar system to 12 planets
Post by: Cyberpumpkin on August 17, 2006, 12:22:55 am
Yesss!  Finally, that real-estate I bought on UB313 will be worth something, now that it's designated as a planet!  I knew donating to that weirdo fringe lobby in Congress was the right thing to do!


Title: Re: Plan boosts solar system to 12 planets
Post by: Arne on August 17, 2006, 02:56:39 am
Re: orbiting moons, the earth doesn't revolve around the sun either, but around the shared gravitational center. Maybe that point is inside the radius of the Sol though...

Quote from: rnd internet page
Charon is just under half the size of Pluto. Due to this very small difference in size, some scientists consider Pluto and Charon to be a double planet.

"Size" being half the diameter, i.e. 1/8th the mass and gravity.


Title: Re: Plan boosts solar system to 12 planets
Post by: XR4-IT on August 22, 2006, 11:02:25 pm
I have more on the question: why our moon Luna is not now considered a planet if Charon is now a planet?

Q: Is Pluto a planet?
A: Yes. In fact, Pluto’s large companion named Charon is also large enough and massive enough to satisfy the definition of “planet”. Because Pluto and Charon are gravitationally bound together, they are actually now considered to be a “double planet.”

So that still sounds like a contradiction of the definition.

Q: What is a “double planet”?
A: A pair of objects, which each independently satisfy the definition of “planet” are considered a “double planet” if they orbit each other around a common point in space that is technically known as the “barycentre”. In addition, the definition of “double planet” requires that this “barycentre” point must not be located within the interior of either body.


I have more on this in my blog…

http://volerum.blog.com/967795/
http://volerum.blog.com/984093/


Title: Re: Plan boosts solar system to 12 planets
Post by: Arne on August 23, 2006, 08:30:07 am
The 'barycentre' in a tripple body system would require some sort of exception rule, such as adding masses together.

Mesklin is not round.

What are their rules for moons anyways?


A 'feel good' solution for me would be: Smaller than Mercury, it's a planetoid. Smaller than 'round', it's an asteroid.

Still, I'd be inclined to call an earth-like body around a gas giant a planet.

It seems we need a table with dimensions or the most important aspects of celestial bodies, then a word for each combination of these properties. Earth orbiting Jupiter would be a: Class 3 size body with atmosphere that orbits an orbiter. Our moon would then be a: Class 2 size body without (significant) atmosphere that orbits an orbiter orbiter.


Title: Re: Plan boosts solar system to 12 planets
Post by: Death 999 on August 23, 2006, 05:17:56 pm
The best proposal I've seen is that a planet must dominate its orbit, such that everything else in the orbit is synchronized to it, be it as a moon, a lagrange point, or a harmonic relationship (such as between Neptune and Pluto).

Pluto hardly clears its orbit out, Ceres even less so; all the other planets do.


Title: Re: Plan boosts solar system to 12 planets
Post by: Razorback on September 07, 2006, 11:06:09 pm
The biggest reason that the Moon is not considered part of a double-planet system is that the earth-moon barycenter is about 1/3 of the way from earth's crust to it's core.