Meet the rocks that killed a planet
Back in 2006, the world of astronomy was torn asunder by the controversial decision to demote Pluto. Overnight, the planet was stripped of its status, becoming just a minor planet. Many astronomers, who felt the decision had been usurped by a minority, were furious (as were countless students who laboured to memorise the planetary mnemonic: ‘My Very Educated Mother Just Served Us Nine Pizzas’).
For millennia, man looked up to the heavens certain in the knowledge that there were only six planets. Beyond Saturn there was nothing but empty space and the twinkling stellar wallpaper that surrounded it. Then, in 1781, a British chap called William Herschel had the cheek to discover a brand new planet. It was the first to be discovered since Christ’s birth, it doubled the size of the known solar system and it was called, after some debate, Uranus, to the delight of sniggering schoolboys ever since.