A SpaceX rocket that has lost control has put India's Chandrayaan and NASA's Lunar Reconnaissance Orbiter in danger.
They are orbiting the Moon to collect observations about the impact crater.
The debris of the seven-year-old rocket, that had been launched from Florida, can collide with the Moon as well.
The dry mass of Falcon 9's second stage is about 4 metric tonnes, and it should impact the Moon at a velocity of about 2.58 km/s.
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The aim of the booster was to attempt an interplanetary mission to send a space-weather satellite on a million-mile journey.
''It has been following a somewhat chaotic orbit since February 2015,'' said meteorologist Eric Berger explained in a recent post on Ars Technica.
“This is the first unintentional case [of space junk hitting the moon] of which I am aware,” as per Bill Gray, who writes the widely used Project Pluto software to track near-Earth objects.
This comes after Starlink satellites launched by Elon Musk’s SpaceX nearly struck a Chinese space station called Tiangong.