Out-of-control rocket about to hit the moon is not a SpaceX Falcon 9, astronomers now say: report

A rocket scene set to hit the moon on March 4 may not be from SpaceX after all.

The astronomer credited with discovering the upcoming impact, Bill Gray, announced on Saturday February 12 that he had erred in identifying the rocket as a former SpaceX Falcon 9 rocket stage that helped launch the Deep satellite. Space Climate Observatory in 2015.

Rather, Gray suggests the scene could be part of a Long March 3C rocket that launched China’s Chang’e 5-T1 mission in October 2014. This spacecraft was a predecessor to Chang’e 5, the 2020 mission who performed a robotic return of lunar samples. .)

Gray manages the Project Pluto software used to track near-Earth objects and posted a correction notice on its website Saturday, Feb. 12 after receiving a note from NASA Jet Propulsion Laboratory engineer Jon Giorgini.

“He [Giorgini] wrote to Gray on Saturday morning explaining that the trajectory of the DSCOVR spacecraft did not come particularly close to the moon, so it would be a bit odd if the second stage moved far enough away to hit it,” wrote Eric Berger on Ars Technica, who first reported the errant recall three weeks ago on Saturday.

Video: The rocket stage will hit the moon, seen by the virtual telescope project

The rocket stage, regardless of its origin story, is still set to crash into the far side of the moon on March 4 at 7:25 a.m. EDT (1225 GMT), and it won’t be visible from Earth. Nonetheless, Gray explained on his website why he believed he made a mistake in identification.

“Prompted by Jon’s email, I dug through my email archives to remember why I had originally identified the subject as the DSCOVR stage in the first place, seven years ago. I did this by digging with confidence it would prove the object was, in fact, the second stage of the DSCOVR,” Gray wrote in his update.

It was using data from the Catalina Sky Survey which typically tracks near-Earth objects to assess threats to Earth, Gray wrote. Catalina found an object about a month after launching DSCOVR, designated WE0913A and initially believed to be a natural object.

“Soon after, an astronomer in Brazil noted on a chat group that the object was orbiting the earth, not the sun, suggesting it could be a man-made object. “, said Gray. After a conversation with the astronomer, Gray and other researchers discovered that WE0913A had passed the moon two days after DSCOVR’s launch.

“I and others have come to accept identification with the second stage [of Falcon 9] as correct. The object had about the brightness we expected, and had come in at the expected time and was moving in a reasonable orbit,” Gray continued, but noted that the evidence was “circumstantial” rather than fully conclusive.

“In hindsight,” Gray continued, “I should have noticed some odd things about WE0913A’s orbit. Assuming there were no maneuvers, it would have been in a somewhat odd orbit around the earth before the lunar flyby. At its highest point it would be close to the moon’s orbit; at its lowest (perigee), about a third of that distance. I would have expected the perigee be near the surface of the earth. The perigee seemed quite high.”

At first, Gray thought that these variations could be due to leakage of remaining fuel, which is very common in older rocket stages. That said, such a change in DISCOVR’s trajectory would have required an unusual amount of fuel, although still possible.

“I didn’t have a trajectory for DSCOVR at the time, and the lunar flyby seemed quite plausible. [as] spacecraft often use a lunar flyby to adjust their orbits,” Gray said. But after receiving the email, he searched the records for an object launched shortly before March 2015, into a “high passing orbit.” in front of the moon “that few spacecraft reach.

This led him to Chang’e 5 T1; the evidence is still not entirely conclusive and based on running its projected orbit in time, but added confidence comes from Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics who typically tracks space objects and junk spatial.

“McDowell sent orbital elements for an amateur radio cubesat that got a ‘carpool’ with the booster, and it’s a very close match,” Gray wrote, adding. “In a sense, it’s still ‘circumstantial’ evidence. But I would consider it pretty compelling evidence.”

Follow Elizabeth Howell on Twitter @howellspace. Follow us on twitter @Spacedotcom Or on Facebook.