The evidence comes from a new study published in Nature Geoscience, which analyzed the chemical composition of lunar rocks brought back from the Apollo missions. The study found that the moon's composition is highly similar to that of Earth's mantle, indicating that the moon was once part of Earth.
The most widely accepted theory is the "giant impact hypothesis," which suggests that around 4.5 billion years ago, a Mars-sized object collided with Earth. This collision caused debris to be ejected into space, which eventually coalesced to form the moon.
No, the moon is gradually moving away from Earth at a rate of about 1.48 inches (3.78 cm) per year. This is due to tidal forces between the Earth and moon, which cause the moon to slowly drift away from Earth.
The study found that the moon's composition is most similar to that of Earth's mantle, but it also shares some similarities with other space objects such as asteroids and Mars. However, the moon's composition is still unique and distinct from these other objects.
This study provides strong evidence for the giant impact hypothesis and further supports the idea that the moon was once part of Earth. It also helps to explain some of the similarities and differences between the moon and Earth, and provides new insights into the formation and evolution of our closest celestial neighbor.