Just over 95% of our Universe comes in the shrouded form of dark energy and matter that we can neither explain nor directly detect. Together, these two dark entities play out a cosmic battle of epic proportions, with the gravity of dark matter slowly pulling structures in the Universe together, and dark energy fuelling the Universe’s accelerated expansion, making it ever harder for those structures to grow. Catherine Heymans has used the world’s best telescopes to map out the invisible dark matter in our Universe and compare different theories on the dark universe.