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Padawan
2004-Jun-07, 12:32 PM
i've noticed that most objects (in space, not atoms and such) orbit close to the rotational center of a massive object. Why is that?

Mainframes
2004-Jun-07, 02:18 PM
I would have thought it is because of the conservation of angular momentum within the solar system originating from the collapse of the dustand gas cloud from which it was created.

Basically the same reason why we have the ecliptic which most planets orbit to within a couple of degrees.

Normandy6644
2004-Jun-07, 02:30 PM
I would have thought it is because of the conservation of angular momentum within the solar system originating from the collapse of the dustand gas cloud from which it was created.

Basically the same reason why we have the ecliptic which most planets orbit to within a couple of degrees.

Yeah, I think of all the planets only Pluto has a really high inclination orbit, most of the others are pretty close to the same plane. It probably does have to do with the original dust cloud that formed the planets, seeing that the cloud would have been essentially in a single plane. When the planets formed, they just stayed in or near within a few degrees here or there.

TravisM
2004-Jun-07, 04:14 PM
Rotational center might imply satellites? We put those in the equatorial plane for a reason. I don't know if you could say 'most' because there are quite a few polar orbiting satellites as well...

bugbread
2004-Jun-07, 05:05 PM
Rotational center might imply satellites? We put those in the equatorial plane for a reason. I don't know if you could say 'most' because there are quite a few polar orbiting satellites as well...

Well, for manmade satellites, we use the equator in order to have geostationary orbits, and can launch nongeostationary satellites anywhere we please, as long as they circle the Earth's center of mass. I think the question was about naturally occurring satellites (moons and such)

tracer
2004-Jun-07, 08:30 PM
Yeah, I think of all the planets only Pluto has a really high inclination orbit,
And Pluto shouldn't even be called a planet. :P

Normandy6644
2004-Jun-07, 09:19 PM
Yeah, I think of all the planets only Pluto has a really high inclination orbit,
And Pluto shouldn't even be called a planet. :P

I had written something about that in my original post, but decided to leave it out. 8)

Jpax2003
2004-Jun-08, 01:17 PM
Don't forget about tidal forces... If Jupiter causes a wobble in the star, then that wobble might affect the orbits of other planets and objects around the star. But I think the tidal forces in the beginning is why the planets orbit near the sun's equatorial plane now. The tidal force didn't put us here, but it made us here and keeps us here.

gmiller
2004-Jun-09, 04:41 PM
This was the question of the day on a Quirks and Quarks show (Google search will provide free audio MP3s!). The answer was that you start out with a big cloud of dust (probably slowly condensing), then something flys past/trhough it which causes it to start to spin. The spin causes it to stretch out and flatten (think of spinning a plate of Jello). The spin has to be just right so that it's not so fast it blows the cloud apart, but fast enough to keep it from collapsing to a single point. As the particles clump together, a new solar system or galaxy is formed.

Mainframes
2004-Jun-10, 11:34 AM
Rotational center might imply satellites? We put those in the equatorial plane for a reason. I don't know if you could say 'most' because there are quite a few polar orbiting satellites as well...

Well, for manmade satellites, we use the equator in order to have geostationary orbits, and can launch nongeostationary satellites anywhere we please, as long as they circle the Earth's center of mass. I think the question was about naturally occurring satellites (moons and such)

Also launching from the equator gives a free velocity bonus if launching in same rotational direction as the earth.