A massive asteroid will brush past the Earth next month - and it is almost as wide as the world's tallest building. The 2000 QW7 asteroid is up to 650m in diameter, which is just a little bit shorter than Dubai's Burj Khalifa, which is 828m high. "It will be over a million kilometres away from Earth, so at a very safe distance - but what's alarming is that it is so big and these asteroids, which are hundreds of metres in size, are more rare than the ones we have been talking about recently, whic