The rocket that will hit the moon has been misidentified

(CNN) – According to NASA, a rocket that was expected to smash into the moon on March 4 has been identified as the stage of a SpaceX Falcon rocket, and instead likely came from a previous Chinese lunar mission.

An object about to collide with the Moon was first detected by Bill Gray, an independent researcher who focuses on orbital dynamics and developer of astronomical software. He identified it in 2015 as the second stage of the SpaceX Falcon rocket, which was used in the same year to launch a rocket DSCOVR United States Deep Climate Observatory.

He said the object, which asteroid watchers initially named WE0913A, passed close to the moon two days after DSCOVR launched.

“We came to accept the second stage identification as correct. The object was as bright as expected, appeared at the expected time and was moving in a reasonable orbit,” Gray said on his website.

Its rating has been widely accepted by Other space experts and NASAwho said he was watching the trajectory of the missile.

new definition

However, over the weekend, Gray said he mistook the object’s origin after calling John Giorgini of NASA’s Jet Propulsion Laboratory, which does not track space debris but does track space debris. Several active spacecraft, including DSCOVR.

John noted that JPL’s Horizons system showed that DSCOVR’s trajectory did not come particularly close to the Moon. It would be a little strange if the second phase passed directly in front of the Moon, while DSCOVR was in another part of the sky. There’s always, said Gray. There might be a gap, but that gap was suspiciously wide.”

Analysis by the Center for Near-Earth Object Studies at NASA’s Jet Propulsion Laboratory indicates that the object expected to impact the far side of the moon on March 4 is likely to be the Chinese booster Chang’e 5-T1 that was launched in 2014. , according to a NASA statement released Monday.

“This is not the SpaceX Falcon 9’s second stage of a 2015 mission as previously reported. This update is the result of an analysis of the object’s orbits in 2016-2017.”

Gray said he reviewed his data later and now came to a different interpretation: The body was the third stage of the Chinese Long March 3C rocket. Used to launch the Lunar Orbiter in 2014.

The rocket stage is expected to hit the moon at 7:26 a.m. ET on March 4. However, the impact will occur on the far side of the Moon and will not be visible from Earth. The missile is likely to disintegrate upon impact and create a crater with a diameter of 10 to 20 meters.

The need for formal control of space debris

Jonathan McDowell, astronomer at Harvard and Smithsonian Center for Astrophysics, He said that identifying space debris “is not at all easy” in deep space orbit, but said that Gray’s new identification may have been correct. “I’d give at least an 80% maybe a 90% chance.”

“It’s especially difficult for these objects in the chaotic orbits of deep space, where you pick up something several years after you last saw it and try to come back to match a known mission,” he explained.

McDowell said the confusion over the rocket’s stage identity has highlighted the need for NASA and other government agencies to monitor deep space debris, rather than relying on the limited resources of personnel and academics.

He said there are 30 to 50 objects missing in deep space, such as the rocket stage, which have been missing for years, but that no space agency has systematically tracked space debris away from Earth.

“It’s not like LEO material, where traffic is high, so debris is a hazard to other spacecraft. But you might think it’s good to know where to drop things.”

“It’s not a very high priority,” he added, “but you would think the world could hire at least one person to correct this, and maybe ask space agencies to announce their paths in deep space.”

More spacecraft will enter this type of orbit in the future, Gray said, and keeping “outer space clean” will have to be considered. There are simple steps government agencies and missile launchers can take, such as publishing the most recent known orbital data.