The Moon Exploration

 The Moon can be an intimidating presence in the night sky, since it's so much bigger than any of the other celestial bodies you can see from Earth. But as you look at it, you should realize that you're seeing just one-half of this natural satellite; the far side of the Moon always faces away from us and we never get to see it. Why does this happen? What makes the Moon shine? And why does it take about 29 days for our satellite to circle the Earth once?

Moon

Craters: Birth Marks of Ancient Catastrophes

The craters on the moon are not only fascinating to look at, but they also hold important clues about the history of our solar system. These impact crater scars are evidence of ancient collisions between the moon and other objects in space. By studying them, we can learn more about the early days of our solar system and how it has evolved over time.

Where Is the Far Side?

The far side of the moon is the hemisphere that always faces away from Earth. Because of this, it's also sometimes called the dark side of the moon. The first time humans saw the far side was during the Apollo 8 mission in 1968. Despite popular belief, the dark side is not actually darker than the near side. In fact, both sides experience about the same amount of sunlight. However, because the far side is permanently shielded from view from Earth, it's often referred to as the dark side.

Who Named It?

The moon was first discovered by the Sumerians in Mesopotamia around 4,000 BCE. They named it Nanna, after the goddess of the moon.

What Happened to it?

For billions of years, the moon was Earth's only natural satellite. But, about 4.5 billion years ago, something happened that changed everything. A Mars-sized object, known as Theia, collided with Earth. The impact was so great that it blasted material from both Earth and Theia into orbit around our planet. Over time, this debris coalesced and formed our moon.

How Long Has It Been There?

Though the moon has been with us since the beginning of time, it wasn't until 1609 that we got our first up-close look, thanks to Galileo Galilei and his telescope. Since then, we've learned quite a bit about our celestial neighbor. For example, we now know that the dark patches on its surface are actually vast plains of lava that cooled long ago. And though it may look like a dead world, there is evidence that the moon may have once had an atmosphere and water on its surface.

How About an Ocean on Its Surface?

Did you know that the moon may have an ocean on its surface? This is just one of the many fascinating features of our nearest celestial neighbor. The moon's surface is actually quite diverse, with different regions having unique characteristics. And its phases, which we can see from Earth, are caused by its orbit around our planet.

But the moon is more than just a pretty face. It has also been the subject of much exploration, both by robotic probes and by human astronauts.

Traveling Around the Far Side by Lunar Shuttlecraft

China's Chang'e-4 lunar rover made history when it became the first spacecraft to land on the far side of the moon. The landing site, called the Von Karman Crater, is in a region that is permanently dark and has a much different composition than the near side of the moon.

What Type of Rock Is That Anyway?

The moon is covered in a dark, basaltic rock called lunar regolith. This powdery substance is the result of billions of years of collisions with meteorites, micrometeoroids, and other space debris. The regolith is also full of craters, which were created by even more impacts.

When Does it Look Different from Our Side Here on Earth?

The Moon's orbit around Earth is elliptical, so sometimes the Moon is closer to Earth than at other times. When it's closer, it looks bigger in the sky. And when it's farther away, it looks smaller.