Data
Table of Contents
1. Solar System Data
1.1. Earth
Constant | Value | Source |
---|---|---|
Earth's equatorial radius | 6 378 136.6(1) m | [1] |
Mean Solar Day | 86400s | [1] |
Orbital Period ("sidereal year") | 365.256 363 004 days | [1] |
Mean equatorial gravity ("g") | 9.780 327 8 (10) m/s2 | [1] |
Earth Mass | 5.9724×1024 kg | [2] |
Semimajor axis | 149.596×106 km | [2] |
Perihelion | 147.092×106 km | [2] |
Aphelion | 152.099×106 km | [2] |
Mean orbital velocity | 29.78 km/s | [2] |
Max. orbital velocity | 30.29 km/s | [2] |
Min. orbital velocity | 29.29 km/s | [2] |
Obliquity ("axial tilt", ε) | 23° 26′ 21.406″ (23.43655°) | [3] |
Notes:
- The orbital period is measured in units of mean solar day (86,400 seconds)
- The obliquity for the Earth varies over a 41,000 year period (Milankovitch cycles). It is taken at a standard time (at J2000.0 — 12:00 noon terrestrial time on January 1, 2000), with the understanding it varies slowly over time, as 84381.406000 arc seconds (or 23 degrees + 26 arcminutes + 21.406000 arc seconds exactly; or \(42.190703\pi/18^2 \approx 0.409092600601\) radians).
2. Sources
2.1. Earth
- Useful Constants, International Earth Rotation and Reference Systems Service.
- NASA, Earth Fact Sheet
- J.L. Hilton, N. Capitaine, J. Chapront, et al.,
"Report of the International Astronomical Union Division I Working Group on Precession and the Ecliptic."
Celestial Mech Dyn Astr 94 (2006) 351–367. https://doi.org/10.1007/s10569-006-0001-2