Distance from Earth: mean 149 597 893 km (1 astronomical unit (a.u.)) max. 152 103 000 km min. 147 104 000 km Mean parallax: 8 .794 Distance from centre of the Galaxy: ∼28 000 light-years Velocity round centre of Galaxy: ∼220 km s−1 Period of revolution round centre of Galaxy: ∼225 000 000 years (1 ‘cosmic year’) Velocity toward solar apex: 19.5 km s−1 Apparent diameter: mean 3201 max. 3225 min. 3131 Equatorial diameter: 1391 980 km Density, water = 1: mean 1.409 Volume, Earth = 1: 1303 600 Mass, Earth = 1: 332 946 Mass: 2 × 1027 tonnes (>99% of the mass of the entire Solar System) Surface gravity, Earth = 1: 27.90 Escape velocity: 617.7 km s−1 Luminosity: 3.85 × 1023 kW Solar constant (solar radiation per second vertically incident at unit area at 1 a.u. from the Sun); 1368 W m−2 Mean apparent visual magnitude: −26.78 (600 000 times as bright as the full moon) Absolute magnitude: +4.82 Spectrum: G2 Temperature: surface 5500 ◦C core ∼15 000 000 ◦C Rotation period: sidereal, mean: 25.380 days synodic, mean: 27.275 days Time taken for light to reach the Earth, at mean distance: 499.012 s (8.3 min) Age: ∼4.6 thousand million years
Posted by Carl hendersonDec 02, 2009
Last Updated:
Dec 02, 2009