Three tons of space junk on course to crash onto the moon’s far side

Experts believe it is debris from Chinese rocket that launched spacecraft towards moon in 2014

The leftover portions of a rocket, weighing close to three tons, will smash into the far side of the moon at about 9,300 kph – or 5,800 mph – on Friday, marking the first-ever instance of humans littering a celestial body with space junk without being aimed there.

Based on its trajectory, the debris is expected to crash onto the moon on 4 March, likely leaving behind a small crater that could fit several semi tractor-trailers.

It was initially presumed to be a SpaceX Falcon 9 rocket booster, but scientists led by Vishnu Reddy from the University of Arizona in the US have been closely monitoring the spent rocket’s rotation and light reflection for weeks and have suggested that it is of Chinese origin.

They believe the space junk is most likely a booster part of a rocket that launched the Chinese spacecraft Chang’e 5-T1, towards the moon in 2014.

While the spacecraft returned to Earth, experts say the booster may have been chaotically moving around in space since then and was sucked in closer to the moon by its gravity recently.

Chinese officials, however, have expressed doubt over this theory.

Researchers said the object could crash somewhere in or near the Hertzsprung crater on the moon’s far side, and carve out a hole about 10m to 20m across, sending moon dust flying hundreds of kilometres across the moon’s barren surface.

“There is particular interest in seeing how impacts produce craters. It’s also interesting from an orbital prediction perspective because it’s traveling between the Earth and moon unpropelled,” Tanner Campbell, a researcher from the University of Arizona said in a statement.

“It’s just an inert rocket body tossed around by its own energy and by solar radiation pressure, so we can evaluate our models and see how good our predictions are,” Mr Campbell added.

Grace Halferty, another researcher part of the analysis, said: “While this isn’t the most detrimental impact, the idea of so many objects in space with unknown orbits and identities is worrying. We need better space traffic management.”

While there have been numerous instances of debris colliding onto the lunar surface since the dawn of moon-focussed exploration missions, including the Soviet Union’s Luna 2 in 1959, experts said the upcoming collision would be the first by space junk that has been zipping around space for almost a decade.

The European Space Agency says more than 12,000 Earth-orbiting satellites have been launched since the beginning of the space age – of which over 5,000 are still operational – with over 36,000 active pieces of debris or space junk.

“We are now in an era where many countries and private companies are putting stuff in deep space, so it’s time to start to keep track of it. Right now there’s no one, just a few fans in their spare time,” Jonathan McDowell of the Harvard and Smithsonian Centre for Astrophysics said.

“There are only a handful of objects in lunar orbit, but I hope this event sheds light on the growing problem of space junk. This science community is concerned about the growing pollution,” Reddy said.