Earth’s Moon and Lunar Phases

The Moon is Earth’s only natural satellite, and it is the only object in space that has been explored by humans in person. Most likely, the Moon formed from a collision between Earth and another object while Earth was still in its early stages of formation. The Moon has no atmosphere, so there is no erosion on the Moon. All of its features remain the same over time.  The Moon is made of the dark, low maria and the lighter highlands, and it is covered with lunar soil called regolith.  People on Earth only see the part of the Moon that reflects sunlight because the Moon's rotation and revolution times are the same.  From Earth, the Moon appears to cycle through phases every 29.5 days as it revolves around the Earth.  The eight phases of the Moon, including the new, full, waxing, waning, and quarter phases, are caused by changing angles relative to the positions of the Earth, Moon, and Sun as the Moon orbits the Earth.