( 15 Sep, 2014) Earth Some Important Facts Published By : upscgk.com Earth Some Important Facts Age 4,550 million years Mass 5.976 x 10kg Volume 1.083 x 10 litres Mean Density 5.518 kg/lt Total Surface Area 510 million sq.km Land Area 29.2% of the total surface area Water Area 70.8% of the total surface area Equatorial Diameter 12,755 km Polar Diameter 12,712 km Escape Velocity 11.2 km/sec Highest Land Point Mount Everest (8,852 m) Lowest Land Point Dead Sea (396 m) Greatest Ocean Depth Mariana Trench (11,033 m) Equatorial Circumference 40,076 km Polar Circumference 40,024 km Mean Surface Temperature 14C Maximum distance from sun (Aphelion) About 152 million km Minimum distance from sun (Perihelion) About 147 million km Rotation Speed 23 hrs, 56 min & 40.91 sec Revolution Speed 365 days, 5hrs & 45.51 sec Dates when days & nights are equal Mar,21 (Vernal Equinox); Sept. 23 (Autumnal Equinox) Dates of longest days and shortest nights June 21 (Summer Solstice); Dec, 22 (Winter Solstice)