History of Epoch

	Revision 4 . . October 24, 2001 5:16 am by Zundark [also, epoch for orbital elements]
	Revision 3 . . October 24, 2001 1:55 am by AxelBoldt [*link]

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Difference (from prior major revision) (no other diffs)

Removed: 3,5d2

In geology, the recent (to the geologist) past is divided into a series of epochs of a few million years each. See Geologic time scale.

Added: 7a5,7

In geology, the recent (to the geologist) past is divided into a series of epochs of a few million years each. See Geologic Timescale.

Changed: 11,12c11,13

In astronomy, an epoch is a moment in time for which celestial coordinates are specified. The position at other times can be computed by taking into account precession and [proper motion]?.

In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. In the case of celestial coordinates, the position at other times can be computed by taking into account precession and [proper motion]?. In the case of orbital elements, it is necessary to take account of perturbation by other bodies in order to calculate the orbital elements for a different time.