The fiery origin of our Moon tied to Earth, as unraveled by scientists through Apollo and now modern missions

Our Moon as seen by the Galileo spacecraft when it flew past on December 7, 1992. Image: NASAWhere did our Moon come from? The origin of Earth’s cosmic companion is a fundamental question in planetary science. From Galileo’s first telescopic observations of the Moon to humans walking on its surface, our understanding of its origins has come a long way. Yet it’s far from complete.Over the decades, scientists have proposed multiple hypotheses to attempt explaining how the Moon came to be. In this article, I focus on the one with the highest consensus among scientists: the Giant Impact Hypothesis (GIH). According to the GIH, a titanic collision took place 4.5 billion years ago, when the planets had just formed in a still-chaotic Solar System. A young Mars-sized planet, named Theia, collided with the newly born Earth. The blistering impact ejected a colossal amount of material. While some of this material escaped to space, the rest stayed in orbit around Earth and coalesced to form the…