Moon - NASA Science
Channel: The Basics Stuffs
Date: 2020-04-15

#learn #explore #improve #moon #Apollo #planet #GK
As NASA marks the 50th anniversary of the Apollo 11 Moon landing, here are five things to know about the Moon that you can share with others:

How far away is the Moon?
How big is the Moon?
What color is the Moon?
Why do we always see the same side of the Moon?
And what are the dark areas on the Moon?

How far away is the Moon?
The average distance from the Moon to the Earth is about 238,855 miles (384,400 kilometers). However, the Moon's orbit around the Earth is not a perfect circle, so the distance between the two objects can vary slightly. At its closest point (called the perigee), the Moon is about 225,700 miles (363,104 kilometers) away from the Earth, while at its farthest point (called the apogee), it is about 251,000 miles (403,700 kilometers) away.

How big is the Moon?
The Moon is the fifth largest natural satellite in the solar system and the largest natural satellite relative to the size of the planet it orbits. It has a diameter of about 2,159 miles (3,474 kilometers), which is about one-quarter the diameter of Earth. Its surface area is about 14.6 million square miles (37.9 million square kilometers), which is about the same as the combined land area of Africa and South America. Despite its size, the Moon has only about 1/81 the mass of Earth.

What color is the Moon?
To the naked eye, the Moon appears to be a pale gray or white color. However, this is not the Moon's true color; rather, it is the result of sunlight reflecting off the Moon's surface. The actual color of the Moon's surface varies depending on the location and composition of the surface material, and it can appear to change slightly depending on the angle and intensity of the sunlight hitting it, as well as the viewing conditions on Earth.

Why do we always see the same side of the Moon?
We always see the same side of the Moon because the Moon's rotation on its axis is synchronized with its orbit around the Earth. This means that the Moon takes about the same amount of time to rotate on its axis as it does to orbit the Earth, so the same side of the Moon is always facing the Earth. This is called tidal locking, and it occurs because the gravitational pull of the Earth causes the Moon's rotation to slow down over time until it becomes synchronized with its orbit. As a result, we only ever see one side of the Moon from Earth.

What are the dark areas on the Moon?
The dark areas on the Moon are called lunar mare, which is a Latin word that means "seas." These dark, smooth plains on the Moon's surface were formed when lava from ancient volcanic eruptions flowed across the surface and cooled. The lunar mare are made up of basalt, a type of rock that is formed when lava solidifies. The basalt is dark in color because it contains iron and other minerals that absorb light. The lunar mare make up about 16% of the Moon's surface, and they can be found on the near side of the Moon as well as the far side.

Credits: NASA Science