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 ring, the phrase is sometimes used critically with the implication of American imperialism, as in the title of Joseph Gerson's book, "The Sun Never Sets: Confronting the Network of Foreign U.S. Military Bases". The empire on which the sun never sets The phrase "the empire on which the sun never sets" has been used with variations to describe certain global empires that were so extensive that there was always at least one part of their territory that was in daylight. It was originally coined for the Spanish Empire, mainly in the 16th and 17th centuries. In more recent times, it