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 Wonderful Flight to the Mushroom Planet They tell the boys that their planet has had a crisis and that everyone is slowly dying of a mysterious sickness. The boys meet up with the king of the planet, the Great Ta, and end up solving the natives' problem, before returning to Earth. The Wonderful Flight to the Mushroom Planet The Wonderful Flight to the Mushroom Planet is a children's science fiction novel written by Eleanor Cameron, illustrated by Robert Henneberger, and published by Little, Brown in 1954. It is set in Pacific Grove, California, and on Basidium, a tiny habitable moon of Earth, invisible from the planet