Scientists say they are sure there is no chance of the 150ft (45.7m) wide space rock hitting the planet. But there is a remote possibility that it could collide with one of more than 100 telecommunication and weather satellites in fixed orbits above the Earth.

The asteroid, 2012 DA14, has been closely tracked since its discovery a year ago. It is predicted to reach its nearest point to the Earth at around 7.30pm UK time on Friday.

Experts have calculated it will stay at least 17,200 miles (27,681km) away - easily far enough to be safe, but a very close shave in astronomical terms. Scientists have never observed such a narrow miss before.

Dr Dan Brown, from Nottingham Trent University, said telecommunication satellites - that ping data between our mobile phones - could be in danger.

Traveling at between 12,427mph (20,000kph) and 18,641mph (30,000kph) - around five miles (8km) a second, or eight times the speed of a rifle bullet - the asteroid will fly inside the orbits of high geostationary satellites some 22,000 miles (35,406km) above the Earth.

''These are the satellites that provide us with telecommunications and weather forecasts,'' said Dr Brown.

''There are loads of them but you're talking about a very big area. It would be very unlucky if a satellite was hit. The asteroid is more likely to hit some space junk, but most of this is only about a centimeter across and the impact won't even be noticed.''