The planets Mercury and Venus do not have any moons and neither does the dwarf planet Ceres. The exploration of Mercury has a minor role in the space interests of the world. Mercury Is The Closest Planet To The Sun And Has A Thin Atmosphere No Air Pressure And An Extremely Mercury Planet Space And Astronomy Earth And Space Science Human Exploration of Mercury. . They are generally solid bodies and few have. When people write just the moon they are usually talking about the moon of the Earth. The physical and orbital characteristics of the moons vary widely. Moons also known as natural satellites orbit planets and asteroids in our solar system. It formed 46 billion years ago from the gravitational collapse of a giant interstellar molecular cloudThe vast majority 9986 of the systems mass is in the Sun with most of the remaining mass contained in the planet JupiterThe four inner system planetsMercury Venus Earth. Discovered i