What can scientists learn from a stray SpaceX rocket hitting the Moon?

A stray SpaceX Falcon 9 rocket, after completing its mission of launching lunar landers, is believed to have crashed into the Moon near the Einstein crater, creating a unique research opportunity for scientists. The empty upper stage of the rocket, weighing around 4,000kg, struck the Moon at a speed of approximately 5,400mph (8,700km/h) on Wednesday, leaving a tiny, brief flash that was difficult to observe even with high-end telescopes.

Amateur astronomers and spacecraft orbiting the Moon were not in the right position to witness the impact live. However, larger observatories in the Americas are now analyzing the information. This accidental collision presents a rare, controlled experiment for planetary geologists, as they can test their models of crater formation and debris ejection.

Understanding the amount of rock and dust thrown up by the impact will help engineers design safer landers and future Moon bases, while also shedding light on the Moon's geology and the Earth-Moon system's formation over 4.5 billion years ago. This is not the first time a human-made object has struck the Moon, as dozens of spacecraft have crashed into it since 1959, some by accident and many deliberately for scientific purposes.