There are literally dozens upon dozens of natural satellites orbiting the planets in our solar system, but only one of those orbits the Earth. The Moon, as we call it, may not look like much more than a bright round space rock in the night sky, but we can assure you, there’s a lot more going on behind the scenes than meets the eye.
It’s theorized that the Moon formed around 4.5 billion years ago after a smaller world slammed into the Earth and left oodles of molten debris in outer space around it. That molten debris is then thought to have coalesced into a solid object, which we call the Moon today. It’s comprised of a Rocky mantle and crust rich in magnesium, oxygen, and silicon, while its inner and outer core are formed from iron.
While the Moon might not look like much more than a dead space rock, some scientists believe that its surface was once geologically active with oceans of molten magma leftover from the collision. As this cooled down to become the Moon we know and love today, the surface became scarred by surface impacts, leaving all those cheese-like craters that can be observed by the naked eye. Notably, scientists have found traces of water ice in craters where the Sun doesn’t shine.
The Moon is the fifth-largest known natural satellite in the solar system behind Ganymede, Titan, Callisto, and Io. This in and of itself is particularly interesting given its size relative to the Earth, which is far from being crowned the largest planet in our solar system, a prestigious title that belongs to Jupiter. Moreover, the Moon is tidally-locked to our planet, which means that the same side always faces the Earth at all times.
NASA’s famous Apollo missions brought humankind to the Moon’s surface for the first time around half a century ago, and with high expectations regarding NASA’s upcoming Artemis program in the foreseeable future, it will indeed be interesting to learn more about Earth’s single most recognizable natural satellite and whether it might be possible to begin colonization on its surface.
Related: Does the Earth have a second Moon?