The Lunar Reconnaissance Orbiter (LRO) – NASA’s eye in the sky orbiting the moon – found the crash site of a mysterious rocket accelerator that struck the far side of the moon on March 4, 2022.
LRO images taken on May 25 revealed not just a single crater, but a double crater formed by the rocket’s impact, a new mystery that astronomers must unravel.
Why a double crater? Although a bit unusual – none of the Apollo S-IVBs that hit the moon created double craters – they are not impossible to create, especially if an object strikes at a low angle. But this does not seem to be the case here.
Astronomer Bill Gray, who first discovered the object and predicted its lunar death back in January, explained that the amplifier “came in about 15 degrees from the vertical. So that’s not the explanation for this.”
The impact site consists of an 18-meter eastern crater superimposed on a 16-meter western crater. Mark Robinson, chief researcher for the LRO Camera team, suggests that this formation of a double crater may be the result of an object with different large masses at each end.
Before (2022-02-28) and after an image (2022-05-21) of the Moon. (NASA / GSFC / Arizona State University)
“Usually a spent rocket has a mass concentrated at the end of the engine; the rest of the rocket stage consists mainly of an empty fuel tank. As the origin of the rocket’s body remains uncertain, the crater’s dual nature could help identify its identity, “he said.
So what is it?
It’s a long story. The unidentified rocket first caught the attention of astronomers earlier this year when it was identified as the upper stage of SpaceX, which launched NASA’s Deep Space Climate Observatory (DSCOVR) to the Sun-Earth L1 Lagrange point in 2015.
Gray, who designed software that tracks space debris, was alerted to the site when the software sent him a ping error. He told The Washington Post on January 26 that “my software complained because it could not project its orbit after March 4 and could not do so because the rocket hit the moon.”
Gray spread the word and the story spread in late January – but a few weeks later he received an email from John Georgini of the Jet Propulsion Laboratory (JPL).
Georgini pointed out that the DSCOVR’s trajectory should not have taken the booster somewhere near the moon. In an attempt to reconcile the conflicting trajectories, Gray began digging back into his data, where he found that he had misidentified the DSCOVR booster back in 2015.
After all, SpaceX was not the culprit. But there was definitely still an object floating toward the moon. So what was it?
A bit of detective work led Gray to determine that this was in fact the upper stage of China’s Chang’e 5-T1 mission, a 2014 technology demonstration mission that laid the foundation for Chang’e 5, which successfully returned a lunar sample to Earth in 2020. By the way, China recently announced that it would follow this sample return mission with a more ambitious project to return a sample to Mars later this decade.
Jonathan McDowell offered some corroborating evidence that seems to support this new theory of object identity.
The mystery was solved.
Just a day later, China’s foreign minister said it was not their amplifier: it had gone out of orbit and crashed into the ocean shortly after the launch.
As it is now, Gray remains convinced that the Change 5-T1 amp hit the moon, suggesting that the Secretary of State made an honest mistake by confusing the Chang’e 5-T1 with a similar name Chang’e 5 (whose booster did indeed sink in the ocean).
As for the new double crater on the moon, the fact that the LRO team was able to find the site of the impact so quickly is an impressive feat in itself. It was discovered only months after the impact with a little help from Gray and JPL, who separately narrowed the search area to several tens of kilometers.
By comparison, the crash site of the Apollo 16 S-IVB took more than six years of careful searching to find.
Bill Gray’s account of the amplifier identification saga is here, as is his relationship to the impact of the double crater. LRO images can be found here.
This article was originally published by Universe Today. Read the original article.
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