An Etymological Dictionary of Astronomy and Astrophysics

Fourth planet from Sun and the seventh largest. Mass 6.42 × 10²⁶ g (0.11 Earth’s), radius 3397 km. Mean distance from Sun 1.52 → astronomical units. → Sidereal period 687 days, → synodic period 779.9 days. Surface temperature 248 K., → rotation period, or → sol, 24h37m22s.6. Mars’ → obliquity is currently 25.19 degrees, but has changed dramatically over billions of years since solar system formation. Atmosphere more than 90% CO₂, traces of O₂, CO, H₂O. Two tiny satellites (→ Phobos and → Deimos), both of which are locked in → synchronous rotation with Mars.

Etymology (EN): Late M.E., from L. Mars the Roman god of war, Ares in Gk. mythology.

Etymology (PE): Bahrâm, from Mid.Pers. Vahrâm, from Vahrân “god of victory,” from Av. vərəθraγna- “victory, breaking the defence, the god of victory.” The first element vərəθra- “shield, defensive power,” cf. Skt. vrtrá- “defence, name of a demon slain by Indra,” Arm. vahagan name of a god (loanword from Iranian). The second element γna-, from Av., also O.Pers., jan-, gan- “to strike, hit, smite, kill” (jantar- “smiter”); cf. Mod.Pers. zadan, zan- “to strike, beat;” Mid.Pers. zatan, žatan;
Skt. han- “to strike, beat” (hantar- “smiter, killer”);
Gk. theinein “to strike,” phonos “murder;” L. fendere “to strike, push;” Gmc. *gundjo “war, battle;” PIE *g^when- “to strike, kill.”