A rocket body collided with the Moon in March this year. The object was observed to be heading toward a lunar collision rate last year.
NASA's Lunar Reconnaissance Orbiter has spotted a crater — which is actually two craters — on the Moon, resulting from the impact that occurred on March 4. The fact that the rocket body has left behind a "double crater" indicates it was not the average rocket. Since the crash landing of the rocket, none of Earth's space-exploring nations have claimed responsibility for the mysterious projectile. This has left NASA scientists baffled as to who was behind the launch.
The Mystery Rocket May Have Had Large Masses At Each End
The eastern crater is 18 metres in diameter, and is superimposed on a western crater 16 metres in diameter, NASA said on its website.
Astronomers had not expected the crater to be a double crater. This could have been formed because the 'mystery rocket' had large masses at each end. A spent rocket mostly has mass concentrated at the motor end, while the rest of the rocket stage mainly consists of an empty fuel tank. The double nature of the crater may indicate the identity of the mystery rocket.
The mystery rocket collided with the Moon near the Hertzsprung crater, which is an impact crater on the far side of the Moon.
The pictures captured by NASA's Lunar Reconnaissance Orbiter show that the wayward debris somehow punched out two overlapping craters when it smashed into the far side of the Moon travelling at roughly 9,290 kilometres per hour, according to an article published by LiveScience.
Mystery Object Could Be A Part Of China’s Chang’e 5-T1 Rocket
Bill Gray, a US astronomer, had predicted that the orbiting piece of space junk would hit the Moon's far side in a matter of months, LiveScience reported.
After spotting the debris for the first time Gray had suggested that it was the second stage of a Falcon X rocket launched in 2015. However, he later speculated that the object was the spent upper stage of China's Chang'e 5-T1 rocket, a spacecraft named after the Chinese moon goddess and launched in 2014. Chinese officials disagreed with the theory and claimed that the rocket's upper stage burned up in Earth's atmosphere several years back.
Experts have predicted that the discarded rocket stage struck the lunar surface at Hertzsprung crater on the Moon's far side, on March 4 at 7:25 am EST (4:55 pm IST).
According to the LiveScience article, NASA's Lunar Reconnaissance Orbiter would have likely documented a plume of lunar dust erupting hundreds of miles high had it been positioned to capture the impact.
Investigating the craters is unlikely to reveal major clues about their controversial origin because the rocket booster probably disintegrated completely upon impact. After the images were released, Gray wrote on his blog that the object is "quite conclusively identified as the Chang'e 5-TI booster".
Mystery Object Was First Spotted In 2015
In March 2015, Gray made his first prediction that the controversial debris would collide with the Moon. This was after the debris was spotted tumbling through space in March 2015.
The mystery object has been assigned the temporary name WE0913A. The Catalina Sky Survey, an array of telescopes near Tucson, Arizona, was the first to spot the object. Gray believed that the object was human-made because it was not orbiting the Sun, but was orbiting Earth instead, unlike what an asteroid does.
How Chang’e 5-T1’s Upper Stage Could Have Created The Crater
Gray thought that the upper stage of China's Chang'e 5-T1 could have created the crater. The mission was launched in October 2014 as part of a preliminary mission to send a test capsule to the Moon and back. When Chinese foreign ministry officials denied claims about the space junk being theirs, and stated that the rocket burned up on its return trip to Earth, US experts suggested that the officials may have confused a similarly designated rocket from a 2020 mission for the 2014 rocket. The experts stated that the 2014 rocket could have hit the Moon.
The US Department of Defense's Space Command, which tracks low-Earth orbit space junk, released a statement on March 1 claiming that China's 2014 rocket never deorbited.
According to the LiveScience article, Gray said an amateur radio satellite or CubeSat was attached to the Chang'e 5-T1 for the first 19 days of its flight, and the trajectory data sent back from that satellite matches the rocket debris' current trajectory perfectly.
NASA Jet Propulsion Laboratory's Center for Near Earth Object studies confirmed Gray's analysis of the orbital data, the article said. Also, researchers at University of Arizona analysed the light spectrum reflected by paint on the crashed debris and identified the rocket as part of the Chang'e 5-T1 mission.
Gray believes that space-faring agencies and private companies should develop better procedures to track the rockets they send into deep space, and this would keep such objects from being mistaken for Earth-threatening asteroids.
Previous Instances Of Human-Made Satellites Crashing Into The Moon
Though rocket body impacts on the Moon have occurred in the past, none of them created double craters. According to 2016 data from Arizona State University, at least 47 NASA rocket bodies have created "spacecraft impacts" on the Moon.
NASA's Lunar Crater Observation and Sensing Satellite was deliberately fired into the Moon's south pole at 9,000 kilometres per hour in the year 2009. This unleashed a plume that enabled scientists to detect the chemical signatures of water ice. NASA intentionally impacted the Saturn V rockets of the Apollo programme on the Moon to dispose of them.
The four craters created by the Apollo S-IVB stages were somewhat irregular in outline and were substantially larger than each of the double craters. These craters were created as a result of the Apollos 13, 14, 15, and 17 missions. The maximum width of the double crater was near that of the S-IVBs.