Quote:
Originally Posted by BigDon
Can a natural object assume a (I don't know the real terms) non-equatorial orbit? I'm not talking about a circumpolar orbit, I mean assume an orbit around, lets say, the 20th parallel (only up high, of course) or do they always have to cut across the parent objects middle or center of gravity?
(Boy, that was poorly articulated)
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No, the orbit must (to a first approximation) lie in a plane with the Earth at one focus of a conic (ellipse, parabola, hyperbola). This is exactly your condition of "cut across the parent object's middle or center of gravity." This means that the plane of the orbit will always cut the Earth in a great circle (ignoring the oblateness of the Earth), thus all orbits must either be in the equatorial plane or in a plane inclined to it. The 20th parallel in your example is not a great circle, its center does not coincide with the center of the Earth, so it is not an eligible plane for an orbit.
That's why when you see one of those "mission control" maps the orbit appears as a wavy curve on a world map. And since the Earth is rotating underneath the orbit (so to speak), the curve doesn't close on itself after going around 360 degrees in longitude but is slightly displaced.