Planet the Drake equation, which estimates the number of intelligent, communicating civilizations that exist in the Milky Way. There are exoplanets that are much closer to their parent star than any planet in the Solar System is to the Sun, and there are also exoplanets that are much farther from their star. Mercury, the closest planet to the Sun at 0.4 AU, takes 88 days for an orbit, but the shortest known orbits for exoplanets take only a few hours, e.g. Kepler-70b. The Kepler-11 system has five of its planets in shorter orbits than Mercury's, all of them much more massive
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