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
Mission: Earth, Voyage to the Home Planet Mission: Earth, Voyage to the Home Planet Mission: Earth, Voyage to the Home Planet is a children's literature book by science writer June A. English and astronaut Thomas David Jones that was published in 1996 by Scholastic. Jones was among the crew members of the Space Shuttle "Endeavour" during an eleven-day mission in space, which was launched in April 1994 to study the ecological well-being of Earth using specialized radar technology. The book, which is illustrated with radar images and picturesque photographs, chronicles the mission and Jones' experiences of it. "Mission: Earth, Voyage to the Home Planet" received a generally