Moon history and iemej..

Moon This article is about Earth's natural satellite. For moons in general, see Natural satellite. For other uses, see Moon (disambiguation). Moon   Full moon as seen from Earth's northern hemisphere Designations Adjectives lunar selenic Orbital characteristics Perigee 362600 km (356400–370400 km) Apogee 405400 km (404000–406700 km) Semi-major axis 384399 km (0.00257 AU)[1] Eccentricity 0.0549 [1] Orbital period 27.321582 d (27 d 7 h 43.1 min[1]) Synodic period 29.530589 d (29 d 12 h 44 min 2.9 s) Average orbital speed 1.022 km/s Inclination 5.145° to the ecliptic[2][a] Longitude of ascending node regressing by one revolution in 18.6 years Argument of perigee progressing by one revolution in 8.85 years Satellite of Earth Physical characteristics Mean radius 1737.10 km (0.273 Earths)[1][3][4] Equatorial radius 1738.14 km (0.273 Earths)[3] Polar radius 1735.97 km (0.273 Earths)[3] Flattening 0.00125 Circumference 10921 km (equatorial) Surface area 3.793×107 km2 (0.074 Earths) Volume 2.1958×1010 km3 (0.020 Earths) Mass 7.3477×1022 kg (0.012300 Earths[1]) Mean density 3.3464 g/cm3[1] 0.606 × Earth Surface gravity 1.622 m/s2 (0.1654 g) Moment of inertia factor 0.3929±0.0009[5] Escape velocity 2.38 km/s Sidereal rotation period 27.321582 d (synchronous) Equatorial rotation velocity 4.627 m/s Axial tilt 1.5424° to ecliptic 6.687° to orbit plane[2] Albedo 0.136[6] Surface temp. min mean max Equator 100 K 220 K 390 K 85°N [7] 70 K 130 K 230 K Apparent magnitude −2.5 to −12.9[b] −12.74 (mean full moon)[3] Angular diameter 29.3 to 34.1 arcminutes[3][c] Atmosphere[8] Surface pressure 10−7 Pa (day) 10−10 Pa (night)[d