Impact craters cover the surface of the moon
(Picture: AP)A four-tonne rocket part was expected to crash into the Moon on Friday afternoon.
The space junk was expected to smash into the far side of the Moon at around 5,800mph, creating a crater between 33ft and 66ft wide - enough to fit two double decker buses.
However, the crash - which was expected to occur shortly after midday - will not be visible from Earth and could take months to confirm with satellite images.
Space junk is a key concern for astronauts, because satellites which provide vital services such as mobile phone signal could be disrupted if they were hit by debris.
However, the astronomer Bill Gray, who first identified the collision course, has said the moon is used to even more serious collisions.
Writing on his blog Project Pluto, Mr Gray said: "Keep in mind that this is a roughly four-ton object that will hit at 2.58 km/s.
"The moon is fairly routinely hit with larger objects moving in the ballpark of 10-20 km/s hence the craters.
"It’s well-built to take that sort of abuse."
The head of space surveillance and tracking at the UK Space Agency, Jacob Greer, said that while this particular bit of debris wasn’t likely to cause significant damage, concerns remained about the amount of space junk in orbit above the Earth.
He said: “This debris could collide at any time with the satellites we depend upon every day for navigation, banking and communications.
“That’s why the UK is taking action, by funding new technology to track or even remove debris from space and working with international partners, including the UN Office for Outer Space Affairs (UNOOSA) to lead efforts to promote space sustainability."
There is around 9,200 tonnes of space debris in orbit, according to the European Space Agency.
Around 34,000 objects are greater than 10cm in size, with the agency estimating there have been 560 break-ups, explosions or collisions.
Of around 6,250 remaining satellites placed by rockets into space since 1957, only around 3,700 are still functioning.
Initially it was believed the rocket part had been launched by Elon Musk’s SpaceX programme after the collision course was identified by Mr Gray in January.
But he later suggested the object was likely to be a Chinese rocket launched in 2014 as part of the Chang’e 5-T1 mission. However, China has denied this.
