wrote in news:1144244869.312028.216920
@v46g2000cwv.googlegroups.com:

What is it?

Thank you,
Christopher Lusardi


I'm not sure that Bill's explanation is quite right. Historically, a
Keplerian trajectory would be a segment of a Keplerian orbit as described
by Keplers first law. This means a segment of an ellipse (or circle as a
circle is just an ellipse with zero eccentricity). The other conic sections
mentioned, a parabola or hyperbolia, which are also solutions to Newton's
laws for a two body problem involving gravity would not qualify, as Kepler
himself did not know of such orbits.

Klazmon.