Comets and asteroids are the building blocks of the planets, relics from the early days of the solar system. They have been witnessed in our skies for millennia - tantalising, yet too small and too distant to study. However, over the course of the past 60 years, developments in astronomy and space exploration have allowed scientists to now see these tiny, mysterious worlds up close - and the Sky at Night has been there every step of the way. Using the Sky at Night archives, Maggie Aderin-Pocock takes us on a journey in pursuit of comets and asteroids - from ancient history to the cutting edge of modern astronomy, from tales of omens seen in our skies to exhilarating space missions straight out of science fiction. Unlike planets and moons, we only get fleeting glimpses of comets and asteroids. It’s that rarity that makes these visitors so special. Who knows what the next one will bring us?