The black marks on the lunar surface are really craters of various sizes that developed in the past as a result of collisions with celestial bodies such as comets, meteorites, and asteroids, which left massive, dug holes following the impact. The darker an area on the Moon, the more rock it contains. The darkest part of the Moon is called the Marius Hills after the 18th century French astronomer who first reported them.
These dark areas do not contain any significant amount of water or minerals that would explain their appearance against the bright background of the Moon. They are just there, and they have been observed since the beginning of modern astronomy. It is estimated that they cover about 1% of the Moon's surface.
It is interesting to note that even though the Sun causes some parts of the Earth to be illuminated while others are in darkness, the overall effect is rather dimming because all parts are surrounded by air which absorbs light of all colors. On the other hand, the Moon never reflects any light from the Sun - it is always dark! This means that no matter where you look on its surface, you will always see a dark place next to a bright one.
The only reason why we can see features on the Moon that are so different from each other is because they have different shapes and angles.
Those black dots, however, are not the same as the dark spots on the sun. The black spots on the sun are colder areas, but the dark spots on the moon are caused by the moon's terrain. The Moon's surface, unlike Earth's, is so prone to asteroid bombardment that it has numerous craters that are little more than deep dents on its surface. These include the large features called mares (pronounced MARES) and vesicles (VEE-sih-bulls).
The most famous crater on the Moon is Crater Lake. It is about 30 miles in diameter and almost completely surrounded by high, steep walls, much like a saucer. The only way to visit this crater is by spacecraft; there is no safe path around it for people or robots.
Crater Lake is very different from other known lunar craters because it is filled with water. The Moon's atmosphere is mostly made of carbon dioxide, so any liquid that forms on the surface will quickly be evaporated. But because the environment within Crater Lake is quite stable, the water remains even though there is no longer any air to evaporate it.
People have wondered about the origin of the water in Crater Lake for many years. Some believe that it came from Earth when asteroids or comets hit our planet and sent billions of gallons of water vapor into space. When that material then collided with the Moon it condensed into ice.
They are known as craters because they were formed as a result of meteorites impacting the Moon. The Moon is constantly evolving through geological processes such as volcanism and asteroid impacts. The impact that formed the Moon about 4.5 billion years ago was so powerful that it created a cavity nearly 300 miles wide and 30 miles deep. This is larger than most countries on Earth.
The lunar surface is made up of several different types of terrain: 90% cratering area, 3% mountain range, 1% plain. There are two reasons why this 1% of plain land is so important. First, it contains all the maria (marshes or lakes) on the Moon: Ocean. Second, it contains all the lunar features used by astronauts to navigate their spacecraft: Holes, pits, and spikes.
These navigation aids were needed because there are no landmarks on the Moon. All craters look the same from space, so astronauts had to rely on them to find their way around.
You may have seen photos of the Moon's far side taken by astronauts on the Lunar Reconnaissance Orbiter.
These impacts shattered the moon's crust, which eventually filled with massive lakes of lava, forming the dark zones known as maria, or "seas."
The mare are thought to have formed when part of the lunar surface collapsed due to thinning of the lunar crust caused by solar radiation or contraction due to heat from within the moon itself. The resulting crater may be many miles in diameter and quite deep.
The largest of these volcanic depressions is called the Sea of Tranquility. It was here that astronauts from the United States and Russia walked together on 9 July 1969, just three days before the Moon's closest approach to Earth. The event made headlines all over the world.
Scientists now believe that both humans and animals were able to survive on the Moon because there is water trapped under very low-level clouds and ice near the surface. The clouds can change every day depending on how much sunlight is coming out from behind the moon. So even though the Moon isn't actually cold, it has a variable climate dependent on its position in relation to Earth.
You might wonder why the Moon looks so different from place to place. This is because the far side of the Moon is always facing away from Earth, so we cannot see this side.