Earth’s Moon is a bewitching world; the largest object in the night sky, as it floats around in a dark sea flaming with the fires of billions of stars. It is an ancient symbol for that which is feminine, as well as for evanescent beauty and romantic love. Although our Moon is Earth’s closest neighbor in Space, it has kept some haunting secrets of its own, and has kept them very well! For all its closeness, it is still not certain about how or when our Moon was born. In September 2013, scientists announced that Earth’s Moon may be considerably younger than previously believed.
Our large Moon is the fifth largest in our Solar System, and by far the largest circling one of the four inner planets: Mercury, Venus, our Earth, and Mars. Mercury and Venus are moonless, while Mars sports two little moons, Phobos and Deimos. Both misshapen Martian moons are probably captured asteroids, that originated in the Main Asteroid Belt between Mars and the gas giant planet, Jupiter.
A moon is a natural body that orbits around a planet. The moon is kept in its place both by the host planet’s gravity, as well as by its own. Some planets host moons; some do not. Some planets host multiple moons, while others (like our own planet) possess only one. In our own Solar System, the outer gas-and ice-giant planets–Jupiter, Saturn, Uranus, and Neptune–host, by far, the largest number of the moons, which are primarily small and icy bodies far from the heat of our Star.
There are at least five theories explaining how Earth’s large Moon came into being. The theory currently viewed as the most likely is termed the giant impact theory, or (much more playfully), either the Big Splash or the Big Whack theory. According to this model, a hypothetical–and mysterious–doomed Mars-sized protoplanet, named Theia by astronomers, blasted into the ancient Earth billions of years ago, when our Solar System was a young, violent, and dangerous place. This catastrophe caused a large chunk of the primordial Earth’s crust to be blasted off into space, hurling a dazzling multitude of somersaulting moonlets into the sky. Some of this fiery debris was ultimately snared into orbit around our ancient planet about 4.56 billion years ago–and it was eventually squeezed together by the force of gravity to evolve into our own bewitching Moon. This event is thought to have occurred immediately after our Solar System formed.