Part of a SpaceX rocket that exploded seven years ago and was left in space after completing its mission will crash into the Moon in March, experts say.
The rocket was deployed in 2015 to orbit a NASA satellite called the Deep Space Climate Observatory (DSCOVR).
Since then, the second phase of the rocket, or booster, has been fluid in what mathematicians call a chaotic orbit, astronomer Bill Gray told AFP on Wednesday.
It was Gray who calculated the space scrap’s new collision course with the Moon.
The booster passed fairly close to the Moon in January in a meeting that changed its orbit, Gray said.
He is behind Project Pluto, software that makes it possible to calculate the orbit of asteroids and other objects in space and is used in NASA-funded space observation programs.
One week after the rocket stage whizzed close to the Moon, Gray observed it again and concluded that it would crash into the dark side of the Moon on March 4 at more than 5,500 miles per hour (9,000 kilometers per hour).
Gray appealed to the amateur astronomer community to join him in observing the booster, and his conclusion was confirmed.
The exact time and place of the impact may change slightly from his forecast, but there is broad agreement that there will be a collision on the Moon that day.
“I’ve been tracking junk of this kind for about 15 years. And this is the first unintended moon impact we’ve had,” Gray told AFP.
‘Time to start regulating’
Astronomer Jonathan McDowell told AFP that it is possible that similar influences have taken place unnoticed.
“There are at least 50 objects that were left in deep orbit around the Earth in the 60s, 70s and 80s that were just left there. We did not track them,” he said.
“Now we’re picking up a few of them … but many of them we can not find, and so they are no longer there,” he added. “Probably at least a couple of them hit the Moon by accident and we just did not notice it.”
The impact of the four-ton SpaceX rocket on the Moon will not be visible from Earth in real time.
But it will leave a crater that scientists will be able to observe with spacecraft and satellites like NASA’s Lunar Reconnaissance Orbiter or India’s Chandrayaan-2, thus learning more about the Moon’s geology.
Spacecraft have been deliberately crashed into the Moon before for scientific purposes, such as during the Apollo missions to test seismometers.
In 2009, NASA launched a rocket scene that plunged into the Moon near its south pole to search for water.
But most rockets do not go that far from Earth. SpaceX brings its rocket amplifiers back through the Earth’s atmosphere so that they dissolve over the ocean. The first phase is recycled and reused.
Gray said there could be more unintentional crashes into the Moon in the future as U.S. and Chinese space programs leave more junk in orbit.
McDowell noted that these events “start to be problematic when there is a lot more traffic”.
“It’s actually nobody’s job to keep track of the junk we’re leaving in deep orbit around the earth,” he added. “I think it’s time to start regulating it.”
SpaceX did not immediately respond to a request for comment from AFP.
Elon Musk’s company is currently developing a lunar lander that will allow NASA to send astronauts back to the Moon by 2025 at the earliest.
© Agence France-Presse