| light-time for travelling one astronomical unit | 8.3 minutes |
| average distance earth to moon | 384,400 km |
| length of the year: | |
| tropical (equinox to equinox) | 365.24219 days |
| sidereal (fixed star to fixed star) | 365.25636 days |
| anomalistic (apse to apse) | 365.25964 days |
| eclipse (moon's node to moon's node) | 346.62003 days |
| length of the month: | |
| tropical (equinox to equinox) | 27.32158 days |
| sidereal (fixed stars to fixed stars) | 27.32166 days |
| anomalistic (apse to apse) | 27.55455 days |
| draconic (node to node) | 27.21222 days |
| synodic (new moon to new moon) | 29.53059 days |
| length of the day: | |
| mean solar day | 24h03m56s.555 = 1d.00273791 mean sidereal time |
| mean sidereal day | 23h56m04s.091 = 0d.99726957 mean solar time |
| sidereal rotation period of the Earth | 23h56s04.099 = 0d.99726966 mean solar time |
| figure of the earth: | |
| equatorial radius | 6,378.140 km |
| polar radius | 6,356.755 km |
| mass of the earth | 5.9742 X 1024kg |
| mass of the moon | 7.3483 X 1022 kg |
| mass of the sun | 1.989 X 1030 kg |
| the galactic system: | |
| pole of galactic plane | µ12h49m.0, d + 27°24' |
| point of zero longii | µ17h42m.4, d - 28°55' |
| galactic longitude of North Celestial Pole | 123°.00/s |
| solar motion with respect to bright stars | 20.0 km/s |
| Period of revolution of Sun about centre of the galacy | 2.2 X 108 yr |
| Conversion factors: | |
| light-year | 9.4607 X 1012 km = 63,240 a.u. = 0.30660 pc |
| parsec | 30.857 X 1012 km = 206,265 a.u. = 3.2616 l.y. |