The Lunar Reconnaissance Orbiter (LRO) – NASA’s eye-in-the-sky in orbit around the Moon – has found the crash site of the mystery rocket booster that slammed into the far side of the Moon on March 4, 2022.
LRO images taken on May 25 revealed not only a crater, but a double crater formed by a rocket impact, revealing a new mystery to astronomers.
Why Double Crater? Although somewhat unusual – none of the Apollo S-IVBs that collided with the Moon produced double craters – they are not impossible to make, especially if an object collides at a low angle. But that doesn’t seem to be happening here.
Astronomer Bill Gray, who first discovered the object and predicted its lunar demise in January, explains that the booster “came at about 15 degrees from vertical. So this is not an explanation for it.”
The impact site consists of an 18-metre-wide eastern crater superimposed on a 16-metre-wide western crater. Mark Robinson, principal investigator of the LRO camera team, proposes that this double crater formation may have resulted from a separate, large-mass object at each end.
Before (2022-02-28) and after (2022-05-21) image of the Moon. (NASA/GSFC/Arizona State University)
“Typically a spent rocket has the mass concentrated at the end of the motor; the rest of the rocket stage consists primarily of an empty fuel tank. Since the origin of the rocket body remains uncertain, the dual nature of the crater indicates its identity.” can help,” he said.
then what is it?
This is a long story. The unidentified rocket first came to the attention of astronomers earlier this year when it was identified as the SpaceX upper stage that launched NASA’s Deep Space Climate Observatory (DSCOVR) at Sun-Earth L1 Lagrange point in 2015 .
Gray, who designs software that tracks space debris, was alerted to the object when his software pinged an error. They told Washington Post On January 26 that “my software complained because it could not project to orbit after March 4, and it could not do so because the rocket hit the Moon.”
Gray spread the word, and the story made the rounds in late January — but a few weeks later, he received an email from John Giorgini at the Jet Propulsion Lab (JPL).
Giorgini reported that DSCOVR’s trajectory should not have taken the booster anywhere near the Moon. In an effort to reconcile the conflicting trajectories, Gray began digging back into his data, where he discovered he had incorrectly identified the DSCOVR booster in 2015.
SpaceX was not the culprit after all. But surely there was still an object hitting the Moon. So what was it?
A little detective work led Gray to determine that it was in fact the upper stage of China’s Chang’e 5-T1 mission, a 2014 technology demonstration mission that would lay the groundwork for Chang’e 5. It successfully returned a lunar sample to Earth in 2020. (Incidentally, China recently announced that it would follow up this sample return mission with a more ambitious Mars sample return project later this decade).
Jonathan McDowell offered some corroborating evidence that appears to strengthen this new theory for object identification.
Mystery solved.
Except, a few days later, China’s foreign minister claimed that it was not their booster: it fell into the sea shortly after launch and crashed.
As it stands now, Gray is convinced that it was the replacement 5-T1 booster that hit the Moon, proposing that the foreign minister made an honest mistake, renaming the Chang’e 5-T1 to the similarly named Chang’e 5. (whose booster did actually sink in the ocean).
As far as the new double crater on the Moon is concerned, the fact that the LRO team was able to find the impact site so quickly is an impressive feat in itself. It was discovered only a few months after the impact, with a little help from Gray and JPL, who independently narrowed the search area to a few dozen kilometers.
For comparison, it took more than six years to find the Apollo 16 S-IVB impact site.
Here’s Bill Gray’s account of the booster detection saga, as well as his thoughts on the double crater effect. LRO images can be found here.
This article was originally published by Universe Today. Read the original article.
