About the size of a minibus, the space rock, known as 2023 BU, will whip over the southern tip of South America just after midnight GMT.

This one was only picked up last weekend by amateur astronomer Gennadiy Borisov, who operates from Nauchnyi in Crimea, the peninsula that Russia seized from Ukraine in 2014.

That's how astronomers can be so confident it will miss the planet, even though it will come inside the arc occupied by the world's telecommunications satellites, which sit 36,000km (22,000 miles) above us.

Prof Don Pollacco from the University of Warwick, UK, told BBC News: "There are still asteroids that cross the Earth's orbit waiting to be discovered.

"Depending on what 2023 BU is composed of it is unlikely to ever reach the Earth's surface but instead burn up in the atmosphere as a brilliant fireball - brighter than a full moon.

"However, there are likely many asteroids out there that remain undiscovered that could penetrate the atmosphere and hit the surface to cause significant damage - indeed many scientists think we could be due such an event."