Last year, a chunk of man-made space material smacked into the hidden part of the moon, puzzling scientists at first. After some serious space detective work, research has suggested it was probably a Chinese rocket booster, and there was something mysterious stuck to it.
Mysterious crashing of Chinese rocket into moon
It was puzzling when on March 4, 2022, WE0913A was seen crashing into the moon, creating an oddly shaped double-crater. Initially thought to be a piece of a SpaceX Falcon 9 rocket, later signs hinted it was a booster connected to China’s Chang’e 5-T1 lunar mission. Despite this, China said it wasn’t involved.
Now, experts from the University of Arizona, California Institute of Technology, Project Pluto, and the Planetary Science Institute are on the case. They tracked the object’s path using telescopes on the ground and concluded that WE0913A was part of a Chinese Long March rocket from the 2014 Chang’e 5-T1 mission.
Intriguingly, they found clues suggesting the abandoned rocket stage probably also carried an undisclosed payload. The mystery might be closer to being solved.
Evidence put forth by the team
The team put forth their case using two pieces of evidence. First off, as the object descended to the moon’s surface, it didn’t wobble around but spun in an orderly rolling tumble.
Their argument is that this suggests the rocket stage was balanced out by a pretty hefty counterweight to the two engines, each weighing in at 544 kilograms (1,200 pounds).
Tanner Campbell, the main person behind the study and a doctoral student at the University of Arizona’s Aerospace and Mechanical Engineering Department, explained, “Something that’s been in space as long as this is subjected to forces from the Earth’s and the moon’s gravity and the light from the sun.”
“So you would expect it to wobble a little bit, particularly when you consider that the rocket body is a big empty shell with a heavy engine on one side,” Campbell said. “But this was just tumbling end-over-end, in a very stable way.”
He went on to say, “We know the booster had an instrument deck mounted to its top end, but those weigh only about 60 pounds, [or 27 kilograms,] or so. We performed a torque balance analysis, which showed that this amount of weight would have moved the rocket’s center of gravity by a few inches—it wasn’t nearly enough to account for its stable rotation. That’s what leads us to think that there must have been something more mounted to the front.”
Formation of twin craters
The scientists were intrigued by the peculiar twin craters created by the Chinese rocket. An eastern one stretched about 18 meters (59 feet), and a western one about 16 meters (52 feet) wide.
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“This is the first time we see a double crater,” Campbell pointed out. “We know that in the case of Chang’e 5 T1, its impact was almost straight down, and to get those two craters of about the same size, you need two roughly equal masses that are apart from each other.”
As for what the undisclosed payload was, Campbell and the team aren’t holding out for any answers. “Obviously, we have no idea what it might have been—perhaps some extra support structure, or additional instrumentation, or something else,” he mentioned.