On a February morning in 2013, a rock the size of a house appeared without warning in the skies above Russia. The scary thing is that nobody saw it coming. The asteroid that exploded over Chelyabinsk was only about 20 metres across so modest by astronomical standards, but it didn't need to be large to cause chaos. The shockwave from its atmospheric disintegration shattered windows across an enormous area, and more than 1,600 people were injured. The energy released was equivalent to roughly 500 kilotons of TNT, that’s around 33 Hiroshima bombs from an object that not a single monitoring system on Earth had spotted in advance. It was a wake up call that shook the planetary defence community to its core, and directly motivated the development of a new generation of asteroid warning systems. One of them, it turns out, is named after a small African mammal famous for standing guard. The MeerKAT radio telescope (Credit : Morganoshell) Meet MeerKAT….…