The American space agency NASA has warned that a massive asteroid is approaching Earth, describing its size as larger than the "Big Ben" clock in London, and it is moving at a staggering speed of 80,000 km/h. NASA confirmed that the asteroid is on a collision course with Earth's orbit on Monday evening, but it is unlikely to hit the surface of the planet. The distance of the asteroid has been measured to be about 7 lunar distances (the distance of a trip to the moon and back), and there would be a significant impact if it actually struck Earth. More than 100 tons of small space rocks or other debris collide with Earth's orbit every day, but they are much smaller than this asteroid, with some measuring only a few meters in diameter. Astronomical experts say that anything smaller than the average size of a car burns up in the atmosphere and does not pose a threat to Earth. NASA believes that approximately every 2000 years, a meteor the size of a football field is likely to enter the atmosphere and cause destruction on Earth.