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
Monument to the Sun time because the planet installations would have to be from a few hundred meters to several tens of kilometers away from the Sun. Beneath the glass are photo-voltage solar modules with lighting elements which turn on at night, and produce show of light. On the chrome ring that surrounds the photo-voltage solar modules on the Sun, are inscribed the names of all of the saints after which present and previous churches on the Zadar peninsula have been named. Next to their names and the date of their feast are the declination and the altitude of the Sun north or south