An 8,800-pound SpaceX Falcon 9 rocket booster slammed into the moon very early Wednesday in a rare man-made collision with the lunar surface, scientists confirmed. The rocket, about 45 feet long and 12 feet wide, hit with a force of nearly 3 tons of TNT. The crater it created could be 100 feet wide and 16 feet deep.
According to CBS News, a plume of sodium and lithium gas was observed by the Very Large Telescope in Chile using spectroscopy, confirming the collision had occurred. Another scientist also detected a sodium emission from an observation site in Sudbury, Massachusetts.
"There's only so many times where events like this will occur, and it gives us a chance to understand how the atmosphere of the moon works," said Carl Schmidt, a planetary scientist at Boston University's Center for Space Physics. "It's happened twice in my lifetime."
The upper stage was originally part of a mission that launched two lunar landers into space in January of last year. Firefly's Blue Ghost-1 ultimately made a successful landing on the moon, while Japan's ispace Hakuto-R crash-landed on the surface. After the landers separated, the Falcon 9 upper stage kept drifting, eventually making its way to the moon's Earth-facing side.
Julianna Scheiman, SpaceX's director of NASA Science and Dragon Programs, said in a news conference Monday the company followed "the appropriate rules and regulations" for properly disposing of the Falcon 9 second stage after launching it last year, but "what has happened is essentially a mixture of solar activity and gravity forces have put it on a path towards the moon."
SpaceX also released a statement Wednesday: "We actively work to be as responsible as possible with hardware left in space to ensure space safety, including for more complex missions. In this case, over time, solar activity and gravity led the second stage toward the Moon. Impacts like this are rare, but they can happen with objects in these types of orbits, and we worked with NASA on the optimal disposal solution."
Independent astronomers first identified the booster's trajectory using publicly available data, according to NASA. NASA's Center for Near Earth Object Studies at the Jet Propulsion Laboratory in Southern California later confirmed the second stage had a 100 percent chance of impacting the moon.
The impact occurred near the moon's Einstein and Bell craters and posed no danger to Earth. It was impossible to see with the naked eye. Even observers with very large telescopes had not been expected to see anything, according to a study released by nearly two dozen scientists ahead of the event.
The impact itself was very quick, and details remain limited. Scientists continue to analyze data from the event.
