Integral – or the International Gamma-Ray Astrophysics Laboratory – is the first space observatory that can simultaneously observe objects in gamma rays, X-rays, and visible light. Its principal targets include gamma-ray bursts and regions in the Universe thought to contain black holes. Integral is helping us understand the black hole at the centre of the Milky Way, as well as those at the centres of other galaxies.

Looking to the future, ESA’s LISA and Athena missions will work both individually and together to address fundamental questions in modern astrophysics. Together, the duo could reveal much about distant and merging black holes, bright quasars in active galaxies, rapid jets around spinning black holes, the cosmic distance scale, and the speed of gravity.

By combining a large X-ray telescope with state-of-the-art scientific instruments, Athena will address key questions in astrophysics, such as how black holes grow and shape their galaxies. Athena will observe hundreds of thousands of black holes, from relatively near to far away, and map the million-degree-hot matter in their surroundings. This includes black holes that formed in the first few hundred million years of the Universe’s long history.

LISA will be the first space-based observatory dedicated to studying gravitational waves, some of which can only be detected using a space observatory that spans millions of kilometres. Using these waves, LISA will be the first mission to probe the entire history of the Universe. Formed of three spacecraft flying in a triangular formation, LISA will help us explore the fundamental nature of gravity and black holes.

Although XMM-Newton, Integral, Athena and Lisa are ESA’s most dedicated black hole missions, other missions are also contributing in big ways. For example, the NASA/ESA/CSA James Webb Space Telescope will help answer the question ‘did black holes form immediately after the Big Bang?’, the NASA/ESA Hubble Space Telescope has found black holes three billion times as massive as our Sun at the centre of some galaxies, and ESA’s Euclid mission, which will probe the dark Universe in greater detail than ever before, could help identify primordial black holes as dark matter candidates.