International Journal of Mars Research | ISSN 2453-8760 | Current Issue: 7 Volume 4

Facts

SK

Orbital characteristics (for Epoch J2000)
Aphelion 249,209,300 km / 1.665 861 AU
Perihelion 206,669,000 km / 1.381 497 AU
Semi-major axis 227,939,100 km / 1.523 679 AU
Eccentricity 0.093 315
Orbital period 686.971 day / 1.8808 Julian years / 668.5991 sols (Martian days)
Synodic period 779.96 day / 2.135 Julian years
Average orbital speed 24.077 km/s
Inclination 1.850° to ecliptic / 5.65° to Sun’s equator / 1.67° to invariable plane
Longitude of ascending node 49.562°
Argument of perihelion 286.537°
Satellites 2 (Phobos, Deimos)
Physical characteristics
Equatorial radius 3,396.2 ± 0.1 km / 0.533 Earths
Polar radius 3,376.2 ± 0.1 km / 0.531 Earths
Flattening 0.005 89 ± 0.000 15
Surface area 144,798,500 km2 / 0.284 Earths
Volume 1.6318 × 1011 km3 / 0.151 Earths
Mass 6.4185 × 1023 kg / 0.107 Earths
Mean density 3.9335 ± 0.0004 g/cm³
Equatorial surface gravity 3.711 m/s² / 0.376 g
Escape velocity 5.027 km/s
Sidereal rotation period 1.025 957 day / 24.622 9 h
Equatorial rotation velocity 868.22 km/h (241.17 m/s)
Axial tilt 25.19°
North pole right ascension 21 h 10 min 44 s / 317.681 43°
North pole declination 52.886 50°
Albedo 0.15 (geometric) or 0.25 (bond)
Surface temperatures 186 K (min), mean 227 K (mean), 268 K (max);−87 °C (min), −46 °C (mean), −5 °C (max)
Angular diameter (from Earth) 3.5–25.1″
Apparent magnitude (from Earth) +1.8 to −2.91