“Two possibilities exist: either we are alone in the Universe or we are not. Both are equally terrifying.”

– Arthur C Clarke

Sentient aliens aside, the Earth is not completely safe from many threats in the galaxy. For instance, sixty-five million years ago, the Earth was irrevocably changed by a catastrophic impact, an asteroid, that even changed the course of millions of years of evolution. “It’s not a matter of if an asteroid will impact again, but when,” says Bruck Syal, postdoctoral researcher at the Lawrence Livermore National Laboratory. “Planetary defence began to be an issue when more and more near-Earth asteroids began to be discovered.” The Chelyabinsk meteorite made headlines in 2013 when it left hundreds of people injured and thousands of structures damaged, which is estimated to be much smaller than the one that led to the extinction of dinosaurs. Humanity has to prepare itself, and perfect methods of defence against large objects from space before we are caught unawares.