ABSTRACT
Mars, the fourth planet in order of distance from the Sun, must have been known since very ancient times, since when at its best it can outshine any other planet or star apart from Venus. Planetary occultations of or by Mars are very rare; the next occasion will be on 11 August 2079, when Mars will be occulted by Mercury. The best pre-telescopic observations of the movements of Mars were made by the Danish astronomer Tycho Brahe, from his island observatory on Hven between 1576 and 1596. William Herschel observed Mars between 1777 and 1783, and suggested that the polar caps were made of ice and snow. Herschel also made the first good determination of the axial inclination of Mars. Energetic observations of Mars were continued during the years before the opening of the Space Age. Before 1964 it was believed that Mars was a world without major mountains or valleys.
