| | Epoch (astronomy) -- Facts, Info, and Encyclopedia article (Site not responding. Last check: 2007-11-06) |
 | | In (The branch of physics that studies celestial bodies and the universe as a whole) astronomy, an epoch is a moment in time for which (Click link for more info and facts about celestial coordinate) celestial coordinates or (Click link for more info and facts about orbital element) orbital elements are specified. |
 | | The currently used standard epoch is (Click link for more info and facts about J2000.0) J2000.0, which is January 1, 2000 at 12:00 ((astronomy) a measure of time defined by Earth's orbital motion; terrestrial time is mean solar time corrected for the irregularities of the Earth's motions) TT. |
 | | Epochs for orbital elements are usually given in ((astronomy) a measure of time defined by Earth's orbital motion; terrestrial time is mean solar time corrected for the irregularities of the Earth's motions) Terrestrial Time, in several different formats, including: |
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