The remaining rocket will crash into the far side of the Moon at 9,300 km/h (5,800 mph) on Friday, far from the prying eyes of telescopes. It can take weeks or even months to confirm the impact with satellite images.
It has tumbled randomly through space, experts say, since China launched it nearly a decade ago. But Chinese officials doubt it is theirs.
No matter who it is, scientists expect the object to dig a hole 33 feet to 66 feet (10 to 20 meters) in diameter and send moon dust hundreds of miles ( kilometers) across the barren, pock-marked surface.
Space debris in low orbit is relatively easy to track. Objects that launch deeper into space are unlikely to hit anything, and these faraway pieces are usually quickly forgotten, except by a handful of observers who like to play celestial detective on the side.
SpaceX originally took the rap for the next lunar litter after asteroid tracker Bill Gray identified the collision course in January. He corrected himself a month later, saying the “mystery” object was not an upper stage of the SpaceX Falcon rocket from the 2015 launch of a deep-space climate observatory for NASA.
Gray said it was likely the third stage of a Chinese rocket that sent a test sample capsule to the Moon and in 2014. But Chinese ministry officials said the upper stage returned in the earth’s atmosphere and had burned up.
But there were two Chinese missions with similar designations – the test flight and the 2020s lunar sample return mission – and US observers believe the two are confused.
US Space Command, which tracks lower space debris, confirmed on Tuesday that the Chinese upper stage of the 2014 lunar mission had never de-orbited, as previously reported in its database. But he could not confirm the country of origin of the object about to hit the moon.
“We are focusing on objects closer to Earth,” a spokesperson said in a statement.
Gray, a mathematician and physicist, said he was now convinced it was the Chinese rocket.
“I’ve become a bit more cautious about these issues,” he said. “But I really don’t see how it could be anything else.”
Jonathan McDowell of the Harvard and Smithsonian Center for Astrophysics supports Gray’s revised assessment, but notes, “The effect will be the same. It will leave yet another small crater on the moon.”
The moon already has countless craters, ranging up to 1,600 miles (2,500 kilometers). With little or no real atmosphere, the moon is defenseless against the constant barrage of meteors and asteroids, and the occasional incoming spacecraft, a few of which have intentionally crashed for the sake of science. Without weather, there is no erosion and therefore impact craters last forever.
China has a lunar lander on the far side of the moon, but it will be too far away to detect Friday’s impact just north of the equator. NASA’s Lunar Reconnaissance Orbiter will also be out of range. Chandrayaan-2, in lunar orbit in India, is unlikely to pass either.
“I had long hoped that something (significant) would hit the moon. Ideally, it would have hit the near side of the moon at a time when we could see it,” Gray said.
After initially pinning Elon Musk’s upcoming SpaceX strike, Gray took another look after an engineer at NASA’s Jet Propulsion Laboratory questioned his claim. Now he’s “pretty fully confident” it’s a Chinese rocket part, based not just on orbital tracking up to its 2014 liftoff, but also on data received from his amateur radio experience. of short time.
JPL’s Center for Near Earth Object Studies endorses Gray’s reassessment. A team from the University of Arizona also recently identified the segment of China’s Long March rocket from light reflecting off its paintwork during telescope observations of the shroud cylinder.
It is about 40 feet (12 meters) long and 10 feet (3 meters) in diameter, and somersaults every two to three minutes.
Gray said SpaceX never contacted him to dispute his original claim. Neither do the Chinese.
“It’s not a SpaceX problem, nor a China problem. No one pays particular attention to what they do with the waste in that kind of orbit,” Gray said.
Tracking the remnants of deep space missions like this is difficult, according to McDowell. The moon’s gravity can alter an object’s trajectory during flybys, creating uncertainty. And there are no readily available databases, McDowell noted, other than those “cobbled together” by himself, Gray and a few others.
“We’re now in a time where many countries and private companies are putting things into deep space, so it’s time to start keeping track of them,” McDowell said. “At the moment there is no one there, just a few fans in their free time.”
Associated Press video producer Olivia Zhang and video journalist Sam McNeil in Beijing contributed to this report.
The Associated Press Health and Science Department is supported by the Howard Hughes Medical Institute Department of Science Education. The AP is solely responsible for all content.
Copyright © 2022 by The Associated Press. All rights reserved.