Terrestrial planet Terrestrial planet A terrestrial planet, telluric planet, or rocky planet is a planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets are the inner planets closest to the Sun, i.e. Mercury, Venus, Earth, and Mars. The terms "terrestrial planet" and "telluric planet" are derived from Latin words for Earth ("Terra" and "Tellus"), as these planets are, in terms of structure, "Earth-like". Terrestrial planets have a solid planetary surface, making them substantially different from the larger giant planets, which are composed mostly of some combination of hydrogen, helium, and water existing in various
The empire on which the sun never sets as "Christopher North" in "Blackwood's Magazine" in 1829, is sometimes credited as originating the usage. However, George Macartney wrote in 1773, in the wake of the territorial expansion that followed Britain's victory in the Seven Years' War, of "this vast empire on which the sun never sets, and whose bounds nature has not yet ascertained." In a speech on 31 July 1827, Rev. R. P. Buddicom said, "It had been said that the sun never set on the British flag; it was certainly an old saying, about the time of Richard the Second, and was not so applicable then as