MARS, the planet which comes next to the earth in order of distance from the sun, is a brilliant star, of a slightly red tint. On examination in a telescope, this colour is found to belong to parte of the surface of 'the planet, which have been conjectured to be land ; the rest, which appears somewhat green, being supposed to be sea. Certain white spots, which appear at each pole after the winter of its hemisphere, and disappear during its summer, have been conjectured to be snow. The apparent diameter of Mars varies from 3".6 to 18'28, being 6".29 when the planet is at its mean distance from the earth. The real diameter is '517 of that of the earth, or about 4100 miles.
Its bulk is .1386 of that of the earth, and its mass is .0000003927 of that of the sun, or about the 2546000th part.
The planet revolves on its axis in 39a and the axis is inclined to the ecliptic 30' 18' 10'1. Its light and heat are 43 per
cent. of those of the earth.
Ekments of the Orbit of Mars.
Epoch 1799, December 31, mean astronomical time at Seeberg. Semiaxis major 1'5236923, that of the earth being assumed as the unit.
Exoentricity .0933070; its secular increase (or increase in 100 years) .000099176.
Inclination of the orbit to the ecliptic P 51' its secular alteration insensible.
Longitudes from the mean equinox of the epoch (1.) of the ascending node 47. 59' 38'4 ; its .secular increase (combined with the precession) 2500"; (2.) of the perihelion 332' 22' 51"; its secular increase (combined with the precession) 6582'; (3.) of the planet (mean) 232' 33' Mean sidereal motion in one mean solar day, 31' 26".655 ; in 365* days ; sidereal revolution 686179645S mean solar days. MARS, or MAYORS. (Ansa.]