Talk:List of non-periodic comets
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[edit] Orbit
In the first pararaph the text "They are usually on near-parabolic orbits that will not return to the vicinity of the Sun for thousands of years, if ever" confuses me a little. My understanding is that an elliptical orbit will always return, a hyperbolic orbit will never return, and a parabolic orbit is the special case at the transition between the two which will "just never return", and which in practice is impossibly unlikely to arise. Therefore, should this text read something like: "They are on hyperbolic orbits that will never return to the vicinity of the Sun"? The suggestion of the possibility of returning in thousands of years contradicts the fact that they are "non-periodic". Is the point being made that we cannot measure some of these orbits accurately enough to know? Whatever, this needs clarification. Matt 03:08, 25 January 2007 (UTC).
- Actually, as an afterthought, the terms "parabolic orbit" and "hyperbolic orbit" probably don't make sense. Should be "trajectories" rather than "orbits"? Matt 03:10, 25 January 2007 (UTC).
