The Moon is a little more than one-quarter the size of Earth, a bizarre characteristic compared to any other natural satellite in our cosmic region. Of all the moons in the solar system, ours is the 5th largest. No other planet that we’re aware of has a moon that is as proportionately big as ours. All other planets with moons that size are massive gas giants. Neptune, the closest in size with a moon that big, is four times the size of Earth.
Without the moon orbiting precisely where it is, it’s possible that life on Earth wouldn’t exist, or at least wouldn’t have evolved to the point that it has. In fact, it is estimated that less than 10 percent of all terrestrial planets in the universe have an Earth to moon ratio like ours, which provides the stability that is necessary to maintain a climate that can harbor life.
The size of the moon is such that it affects our axial tilt, or the way that the Earth wobbles on its axis, changing by a single degree over the course of thousands of years. This relegation to one degree of movement is necessary for climatic stability; without the moon’s balance, the Earth could tilt as much as 85 degrees every million years or so, causing drastic changes. This would adjust the orientation of the Earth to the Sun so significantly that the Sun would shift to be situated directly over the poles rather than the equator where it currently is. Life could not evolve during such radical shifts.
Is The Moon Artificial?
There are two ways that planets typically acquire moons, through accretion or capture. The process of capturing a moon is just like it sounds, a moon will drift into the orbit of a planet and become trapped in its gravitational field.
In the process of accretion, a moon is formed at the same time as the planet from the accretion disk of the solar system. But this theory has been widely dismissed due to the differences in core composition and the fact that the moon is almost a billion years older than the Earth. In fact, the mineral composition of rocks found on the surface of the moon varies drastically from those found on Earth.
The abundance of titanium is one example of such an anomaly, with certain lunar samples containing up to 10 percent of this precious mineral; the highest abundance of titanium-rich minerals on Earth has never exceeded 1 percent. There are other processed metals found on the moon like mica and brass, as well as the presence of radioactive elements like Uranium-236 and Neptunium, none of which are found naturally on Earth.