<Table> Earth <Tr> <Td_colspan="2"> The Blue Marble photograph of Earth, taken during the Apollo 17 lunar mission in 1972 </Td> </Tr> <Tr> <Th_colspan="2"> Orbital characteristics </Th> </Tr> <Tr> <Td_colspan="2"> Epoch J2000 </Td> </Tr> <Tr> <Th> Aphelion </Th> <Td> 152 100 000 km (94 500 000 mi; 1.017 AU) </Td> </Tr> <Tr> <Th> Perihelion </Th> <Td> 147 095 000 km (91 401 000 mi; 0.983 27 AU) </Td> </Tr> <Tr> <Th> Semi-major axis </Th> <Td> 149 598 023 km (92 955 902 mi; 1.000 001 02 AU) </Td> </Tr> <Tr> <Th> Eccentricity </Th> <Td> 6998167086000000000 ♠ 0.016 7086 </Td> </Tr> <Tr> <Th> Orbital period </Th> <Td> 365.256 363 004 d (1.000 017 420 96 yr) </Td> </Tr> <Tr> <Th> Average orbital speed </Th> <Td> 29.78 km / s (107 200 km / h; 66 600 mph) </Td> </Tr> <Tr> <Th> Mean anomaly </Th> <Td> 7000625904740362451 ♠ 358.617 ° </Td> </Tr> <Tr> <Th> Inclination </Th> <Td> <Ul> <Li> 6999124878307980194 ♠ 7.155 ° to the Sun's equator; </Li> <Li> 6998275533383683093 ♠ 1.578 69 ° to invariable plane; </Li> <Li> 6993872664625997166 ♠ 0.000 05 ° to J2000 ecliptic </Li> </Ul> </Td> </Tr> <Tr> <Th> Longitude of ascending node </Th> <Td> 3000803464756118225 ♠ − 11.260 64 ° to J2000 ecliptic </Td> </Tr> <Tr> <Th> Argument of perihelion </Th> <Td> 7000199330266505796 ♠ 114.207 83 ° </Td> </Tr> <Tr> <Th> Satellites </Th> <Td> <Ul> <Li> 1 natural satellite: the Moon </Li> <Li> 5 quasi-satellites </Li> <Li>> 1 400 operational artificial satellites </Li> <Li>> 16 000 space debris </Li> </Ul> </Td> </Tr> <Tr> <Th_colspan="2"> Physical characteristics </Th> </Tr> <Tr> <Th> Mean radius </Th> <Td> 6371.0 km (3958.8 mi) </Td> </Tr> <Tr> <Th> Equatorial radius </Th> <Td> 6378.1 km (3963.2 mi) </Td> </Tr> <Tr> <Th> Polar radius </Th> <Td> 6356.8 km (3949.9 mi) </Td> </Tr> <Tr> <Th> Flattening </Th> <Td> 6997335280000000000 ♠ 0.003 3528 1 / 7002298257222101000 ♠ 298.257 222 101 (ETRS89) </Td> </Tr> <Tr> <Th> Circumference </Th> <Td> <Ul> <Li> 40 075.017 km equatorial (24 901.461 mi) </Li> <Li> 40 007.86 km meridional (24 859.73 mi) </Li> </Ul> </Td> </Tr> <Tr> <Th> Surface area </Th> <Td> <Ul> <Li> 510 072 000 km (196 940 000 sq mi) </Li> <Li> 148 940 000 km land (57 510 000 sq mi; 29.2%) </Li> <Li> 361 132 000 km water (139 434 000 sq mi; 70.8%) </Li> </Ul> </Td> </Tr> <Tr> <Th> Volume </Th> <Td> 7021108320999999999 ♠ 1.083 21 × 10 km (7011259876000000000 ♠ 2.598 76 × 10 cu mi) </Td> </Tr> <Tr> <Th> Mass </Th> <Td> 7024597237000000000 ♠ 5.972 37 × 10 kg (7024597236001731600 ♠ 1.316 68 × 10 lb) (7024596565000000000 ♠ 3.0 × 10 M) </Td> </Tr> <Tr> <Th> Mean density </Th> <Td> 5.514 g / cm (0.1992 lb / cu in) </Td> </Tr> <Tr> <Th> Surface gravity </Th> <Td> 9.807 m / s (7000100000000000000 ♠ 1 g; 32.18 ft / s) </Td> </Tr> <Tr> <Th> Moment of inertia factor </Th> <Td> 0.3307 </Td> </Tr> <Tr> <Th> Escape velocity </Th> <Td> 11.186 km / s (40 270 km / h; 25 020 mph) </Td> </Tr> <Tr> <Th> Sidereal rotation period </Th> <Td> 7004861641003520000 ♠ 0.997 269 68 d (23h 56m 4.100 s) </Td> </Tr> <Tr> <Th> Equatorial rotation velocity </Th> <Td> 0.4651 km / s (1674.4 km / h; 1040.4 mph) </Td> </Tr> <Tr> <Th> Axial tilt </Th> <Td> 6999409092629495479 ♠ 23.439 2811 ° </Td> </Tr> <Tr> <Th> Albedo </Th> <Td> <Ul> <Li> 0.367 geometric </Li> <Li> 0.306 Bond </Li> </Ul> </Td> </Tr> <Tr> <Td_colspan="2"> <Table> <Tr> <Th> Surface temp . </Th> <Th> min </Th> <Th> mean </Th> <Th> max </Th> </Tr> <Tr> <Th> Kelvin </Th> <Td> 184 K </Td> <Td> 288 K </Td> <Td> 330 K </Td> </Tr> <Tr> <Th> Celsius </Th> <Td> − 89.2 ° C </Td> <Td> 15 ° C </Td> <Td> 56.7 ° C </Td> </Tr> <Tr> <Th> Fahrenheit </Th> <Td> − 128.5 ° F </Td> <Td> 59 ° F (15 ° C) </Td> <Td> 134 ° F (57 ° C) </Td> </Tr> </Table> </Td> </Tr> <Tr> <Th_colspan="2"> Atmosphere </Th> </Tr> <Tr> <Th> Surface pressure </Th> <Td> 7005101325000000000 ♠ 101.325 kPa (at MSL) </Td> </Tr> <Tr> <Th> Composition by volume </Th> <Td> <Ul> <Li> 78.08% nitrogen (N; dry air) </Li> <Li> 20.95% oxygen (O) </Li> <Li> 0.930% argon </Li> <Li> 0.0402% carbon dioxide </Li> <Li> ~ 1% water vapor (climate - variable) </Li> </Ul> </Td> </Tr> </Table> <Tr> <Td_colspan="2"> The Blue Marble photograph of Earth, taken during the Apollo 17 lunar mission in 1972 </Td> </Tr>

What is the size of earth in km