At first glance, it appears unlikely that we are under threat from extra-terrestrial objects. Yet, at any moment, the sky could fall on our heads. Our solar system contains millions of objects known as asteroids. The smallest measure just a few centimetres across but the largest can have a diameter of a thousand kilometers. Some circle the sun, like planets, while others cross paths with Earth’s orbit. Now, technological marvels are under construction to avoid a cataclysmic collision. What seemed like science fiction, has now become reality. We are currently learning how to deflect asteroids from their celestial path.