The remains of the upper stage from a SpaceX Falcon 9 rocket will undertake an unplanned extended mission in March when the roughly 4-ton hunk of space junk creates a new crater on the far side of the moon by slamming into it at over 5,000 miles per hour.
The terminal trajectory was first noticed by Bill Gray, an amateur astronomer and software developer in Maine. His software picked up the impact in an orbital model and Gray worked with observatories around the world to gather additional data and increase his confidence in the prediction.
“With all the data, we’ve got a certain impact at March 4 12:25:58 Universal Time (4:25 a.m. PT),” Gray writes in a blog post. Jonathan McDowell, a leading watcher of orbit and everything near Earth in space, confirmed the prediction.
The rocket launched from Florida in 2015, lofting the Deep Space Climate Observatory satellite into orbit before continuing into its own rather erratic elliptical orbit.
Gray expects the spent rocket to crash into the lunar surface in a crater named Hertzsprung that’s a little bit larger than the state of Iowa. The location is remote enough that the impact doesn’t pose any threat to the Apollo mission or other space program landing sites.
SpaceX did not immediately respond to a request for comment.
Besides adding a new feature to the dark side of the moon, there’s some concern it could also introduce tiny hitchhikers to our natural satellite.
“So I’m not bothered by one more crater being made on the moon,” David Rothery, professor of planetary geosciences at the UK’s Open University, wrote in The Conversation. “It already has something like half a billion craters that are 10 meters or more in diameter. What we should worry about is contaminating the moon with living microbes, or molecules that could in the future be mistaken as evidence of former life on the moon.”
This won’t be the first time a spacecraft has slammed into the moon, although Gray thinks it might be the first time it’s happening unintentionally. As recently as 2009, NASA slammed its Lunar Crater Observation and Sensing Satellite (Lcross) into the surface in a search for water (it found some).
“In essence, this is a ‘free’ Lcross… except we probably won’t see the impact,” Gray says.
While the impact and the new crater it creates won’t be visible from Earth, Gray and others are hopeful the Lunar Reconnaissance Orbiter and other spacecraft will eventually be able to get a glimpse of the damage.
“It will be the moon’s newest archaeological site,” writes space archaeologist Alice Gorman. “We’ll learn something about the geology of the location from the color differences and distribution of the ejected material. It’s an opportunity to learn more about the Moon’s mysterious far side.”
In a case of cosmic irony, Gray points out there’s one spacecraft well positioned to view the impact: the Deep Space Climate Observatory, the same satellite that the wayward rocket launched seven years ago.
“Except that it’s about 600,000 kilometers (373,000 miles) away, and tends to stay focused on the Earth; I don’t expect they would swerve it sideways to observe an impact that would probably be too faint for it to observe anyway.”
Someone check with Elon Musk to see about turning on the cameras on that old Falcon 9….