A position snapshot, relative to the parent, that does NOT animate with
time — the whole point of the 6 classical elements is that they let
position be computed at any date, which needs either a real ephemeris
or enough independent observations to fit an orbit. A data source that
only publishes one x/y/z per body, not a time series, can't support
that. Rather than inventing fictitious elements to force a body into the
Keplerian shape, a fixed body just stays where it was captured. See
CelestialBody.orbit/fixedPosition.
A position snapshot, relative to the parent, that does NOT animate with time — the whole point of the 6 classical elements is that they let position be computed at any date, which needs either a real ephemeris or enough independent observations to fit an orbit. A data source that only publishes one x/y/z per body, not a time series, can't support that. Rather than inventing fictitious elements to force a body into the Keplerian shape, a fixed body just stays where it was captured. See CelestialBody.orbit/fixedPosition.