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shapoopy wrote:

Isn't even a moon orbiting a planet (like the Earth) technically a binary system, just to an infinitesimal degree?

No, because the center of mass of the Earth-Moon system is within Earth.

Last edited by Miles (2006-08-26 1:17 am)

I'm not sure why having the hypocenter inside the earth's surface makes a difference.

I was under the impression Pluto got booted because it's orbit intersects Neptune's orbit and is in 'resonance'.  It could be argued that Pluto orbits Neptune.

I'd rather the argument went the other way and we got a few extra planets instead.

I wish we'd go metric.  I get really tired of converting between the systems, like whenever I have to deal with companies outside the US which is pretty often.

Miles wrote:

Kirk wrote:

I'm not sure why having the hypocenter inside the earth's surface makes a difference.

I could very well be making it up.

Hah, this is cute!

Kirk wrote:

I wish we'd go metric.

Then we would only have 5 planets.

Gatchaman wrote:

Kirk wrote:

I wish we'd go metric.

Then we would only have 5 planets.

Nah, c'mon! We would have 10 planets.

ConnertheCat wrote:

D'Eyncourt wrote:

Pluto doesn't count under the new definition because it doesn't 'reign supreme in its own orbit, having "cleared the neighborhood" of other competing bodies' (the Kuiper Belt Objects [KBOs] in the case of Pluto).

Neither has Earth, Jupiter or Neptune - guess they aren't planets either.

The moons of Earth, Jupiter and Neptune are all, scientifically speaking, the planet they're orbiting's bitch. The biggest effect that any of these moons have on their planets is the effect Luna has on Earth. And even then, the moon still orbits earth, not they both orbit each other.

ConnertheCat wrote:

D'Eyncourt wrote:

Pluto doesn't count under the new definition because it doesn't 'reign supreme in its own orbit, having "cleared the neighborhood" of other competing bodies' (the Kuiper Belt Objects [KBOs] in the case of Pluto).

Neither has Earth, Jupiter or Neptune - guess they aren't planets either.

That quote isn't the only criterion, but it is the one which disqualifies Pluto.

D'Eyncourt wrote:

ConnertheCat wrote:

D'Eyncourt wrote:

Pluto doesn't count under the new definition because it doesn't 'reign supreme in its own orbit, having "cleared the neighborhood" of other competing bodies' (the Kuiper Belt Objects [KBOs] in the case of Pluto).

Neither has Earth, Jupiter or Neptune - guess they aren't planets either.

That quote isn't the only criterion, but it is the one which disqualifies Pluto.

The current reason Pluto isn't a planet right now is because Neptune's in it's orbit... guess what, Pluto is also in Neptune's orbit, therefore making it not a planet either.

Why are you so defensive about pluto? It was just a little miserable chunk of ice and rock.

That we aren't defining planets solely by their size? And the fact that they orbit the sun?

Chickenhawk wrote:

That we aren't defining planets solely by their size? And the fact that they orbit the sun?

The way they have it worded currently, they're are zero planets in the Sol system for none of them have "clear orbits", especially Neptune but to a lesser degree the rest of them as well.

BBC News wrote:

Pluto was disqualified because its highly elliptical orbit overlaps with that of Neptune.

But Dr Stern pointed out that Earth, Mars, Jupiter and Neptune have also not fully cleared their orbital zones. Earth orbits with 10,000 near-Earth asteroids. Jupiter, meanwhile, is accompanied by 100,000 Trojan asteroids on its orbital path.

These rocks are all essentially chunks of rubble left over from the formation of the Solar System more than four billion years ago.

"If Neptune had cleared its zone, Pluto wouldn't be there," he added.

Article

Further info in the article talks about the current uproar, even among the IAU (only 4% of the voting members voted).

Edited to fix BBCode error.

Last edited by ConnertheCat (2006-08-26 4:26 pm)

And I'll start the Popular Astronomer's Front!