The Moon and Its Shadows

As seen in the naked eye, the moon is probably the biggest and the brightest celestial object in our sky during the night time. The moon is a round-shaped celestial object, and it is the only object that orbits around the Earth. It is among the 190+ natural satellites that orbit the different planets in our solar system.

The moon was formed over 4.51 billion years ago. There are many different theories about the formation of the moon, but the theory that is considered the most accurate is that the moon was formed from a massive collision of an object almost the size of the planet Mars to the Earth. This giant impact might have broken off the proto-Earth’s different compositions, and it blasted into orbit. Other theories like the moon of the Earth originally was from Venus, the Earth captured the moon, or that the moon was a product of fission of the Earth, are also considered.


The moon is consists of a crust, a mantle, and a very small core. The moon’s core is approximately 480 km wide and is consists of different elements like mostly iron and sulfur. On the other hand, its mantle is about 1 330 km thick and consists of rocks that are made up of iron and magnesium. Lastly, the crust is roughly 70 km deep and is mostly broken and fragmented because of all the huge impacts that were made.

The moon is composed of a compact and rocky surface, just like the terrestrial planets. Its surface is full of craters due to the impact of the asteroids million years ago. The elements present in the moon are oxygen, which is 43 percent of the moon, silicon, which is 20%, magnesium, which is 19%, iron, which comes in 10%, calcium, and aluminum, which both are 3%, and a small amount of chromium in 0.42%, titanium in 0.18%, and lastly, manganese with 0.12%. In terms of water, lunar orbiters discovered evidence of water that may have come from under the ground.



The moon’s atmosphere, called the exosphere, is thin and fragile. Since the moon’s atmosphere is very thin, the heat cannot be trapped on its surface. The temperature during the day on the sunny side of the moon can reach 134°C, while on the darker side of the moon, the temperature reaches -153°C. Take note that since the moon’s atmosphere is very thin and lacks water supply, the moon is not livable.

bright stars, black circle, yellow glowing light around the circle


An eclipse is an example of an astronomical event that happens when a celestial object like the moon or a planet moves and passes into the shadow of another celestial object. An eclipse usually occurs when there is an occultation (when one object completely hides another object) or when there is a transit (when one object partially covers a small part of another object). Two types of eclipses occur on Earth, the Lunar eclipse, and the Solar eclipse.


A Lunar eclipse happens when the moon goes between the sun and the planet Earth. Since the moon orbits the Earth simultaneously the Earth orbits the sun, when the Lunar eclipse happens, the Earth would block the light that is supposed to reach the moon. Instead of receiving the light, the moon would receive the Earth’s shadow. A lunar eclipse can only happen when it is a full moon.

There are two types of lunar eclipses, the total lunar eclipse, and the partial lunar eclipse. A total lunar eclipse happens when both the moon and the sun are directly located on the Earth’s opposite sides. The sunlight that is supposed to reach the moon is refracted by the Earth’s atmosphere because the Earth blocks all the direct sunlight from reaching the moon’s surface. Because of this, the moon appears to have a reddish color, which is why people call it the “blood moon.” On the other hand, a partial lunar eclipse occurs when a minor part of the moon hides behind the Earth’s shadow. A very dark shadow appears on the side of the moon that faces the Earth.


When a Solar eclipse happens, the moon passes in the middle of the sun and the Earth. When this happens, the moon gets all the sunlight that is intended for the Earth. So, during a solar eclipse, the Earth is the one that receives the moon’s shadow.

When a solar eclipse happens, two shadows are cast by the moon. The first is the umbra, where the moon’s shadow appears smaller as it reaches the Earth. The other one is called the penumbra, where the moon’s shadow appears more extensive as it reaches the Earth.