Update: Chinese Moon Litter Impact As Expected, Almost

Xi Jinping has officially been credited with “the first piece of space junk to accidentally impact the lunar surface.” NASA left lots of space junk on the moon but all of that was intentional. China denies the rap but experts know for sure. There’s no doubt at all that it’s part of Chang’e 5-T1. There is a mystery though.

Impact as planned, almost

Researchers who tracked the wandering space litter, in both the private sector and at NASA’s Jet Propulsion Laboratory, were surprised that their trajectory predictions were accurate enough for the impact crater to be spotted on photographs already.

When they found the target, it started a new mystery. Why did the hole have a dumbbell shape?

After wandering aimlessly in space in the Earth-Moon gravity well system since 2014, the booster rocket from the Chang’e 5-T1 lunar mission smacked into the dark side of the moon. It was expected to make a crater 22 yards across. They ended up with two impact craters.

“Surprisingly the crater is actually two craters, an eastern crater (18-meter diameter, about 19.5 yards) superimposed on a western crater (16-meter diameter, about 17.5 yards),” NASA announced Friday, June 24.

After kicking around the possibilities, the engineers are convinced there were two large masses at either ends of the rocket. That’s really strange but would explain the shape of the impact crater.

They expected one huge mass at one end, the engine. The rest of the tube should be empty gas tank. One thing they know for certain, no NASA rocket is built that way. Double craters aren’t impossible to create but generally require the object to come in at a grazing “low angle.” This one came in almost straight down so that won’t explain it.

Previously misidentified

When the piece of space litter was first discovered, by astronomer Bill Gray, he thought Elon Musk was responsible. SpaceX had an airtight alibi when the math proved it wasn’t them. For all sorts of reasons, the Chinese booster has been positively identified as the culprit.

The Chinese denied it but on further investigation everyone realized they thought they were being asked about another mission. The booster for the other Chang’e mission did drop into the sea. It was Chang’e 5-T1 that had an impact date with Luna.

The wayward missile was picked up when an artificial intelligence program written by Gray had a little problem. His “software complained because it couldn’t project the orbit past March 4, and it couldn’t do it because the rocket had hit the Moon.” He ran his figures and picked a spot marked x for it to impact.

Meanwhile, JPL used their top notch gear and DARPA gizmos to plot their own spot. They were closest. Their spot was 8 km from the actual crash site. Gray was still in the neighborhood. He only missed by 16 km. Because of such accurate estimates, finding the new craters was a snap.

According to Universe Today, “the fact that the LRO team was able to find the impact site so quickly is an impressive feat in itself.”

“It was discovered mere months after impact, with a little help from Gray and JPL, who each independently narrowed the search area down to a few dozen kilometers. For comparison, The Apollo 16 S-IVB impact site took more than six years of careful searching to find.“