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 Sam". In 1906, William Jennings Bryan wrote, "If we can not boast that the sun never sets on American territory, we can find satisfaction in the fact that the sun never sets on American philanthropy"; after which, "The New York Times" received letters attempting to disprove his presupposition. A 1991 history book discussion of U.S. expansion states, "Today ... the sun never sets on American territory, properties owned by the U.S. government and its citizens, American armed forces abroad, or countries that conduct their affairs within limits largely defined by American power." Although most of these sentiments have a patriotic