Planetary data for Mercury

mean distance from Sun 57,910,000 km (0.4 AU)

eccentricity of orbit 0.2056

inclination of orbit to ecliptic 7.004°

Mercurian year (sidereal period of revolution) 87.9694 Earth days

maximum visual magnitude -1.9

mean synodic period* 116 Earth days

mean orbital velocity 47.9 km/sec

radius (equatorial and polar) 2,439.7 km

surface area 74,800,000 km²

mass 3.30 × 10²³ kg

mean density 5.43 g/cm³

mean surface gravity 370 cm/sec²

escape velocity 4.3 km/sec

rotation period (Mercurian sidereal day) 58.6462 Earth days

Mercurian mean solar day 175.9 Earth days

inclination of equator to orbit less than 3°; probably nearly zero

magnetic field strength 0.003 gauss

mean surface temperature 440 K (332 °F, 167 °C)

surface temperature extremes 700 K (800 °F, 430 °C) to 90 K (-300 °F, -180 °C)

typical surface pressure about 10^-15 bar

number of known moons none

*Time required for the planet to return to the same position in the sky relative to the Sun as seen from Earth.