Over the past 50 years, astronomers have become increasingly certain that most of the Universe is made up of a mysterious invisible substance that we do not properly understand. This stuff — known as ‘Dark Matter’ — is thought to play an integral role in the evolution of the Universe, and is ultimately responsible for our existence here on Earth. But despite its importance, Dark Matter has never actually been detected! Dr Matt Bothwell lays out the observational evidence that has led scientists to believe something which — on the surface — seems so incredibly bizarre.

Dr Matt Bothwell is Public Astronomer at the University of Cambridge and a science communicator who gives astronomy talks and lectures on almost any area of astronomy, and makes regular media appearances (including local and national TV and radio). When he is not doing outreach, Matt is an observational astronomer, who uses a range of state-of-the-art observing facilities to study the evolution of galaxies across cosmic time.