The space agency said the 2016 NF23 is hurtling rapidly at a speed of around 20,000mph. At that speed, it is around 15 times faster than the 1,354mph the retired Concorde travelled at. The 2016 NF23 also measures up to a jaw-dropping 160metres. At that size, it is bigger than the Great Pyramid of Giza in Egypt which measures 139m. It is listed on NASA's Earth Close Approaches page, despite whizzing by at a distance of 3million miles away. But in space terms, it is considered close enough that it will pay attention to it. At 160m, it is considered...