A black hole is a concentration of mass so strong that nothing can escape its gravitational field. According to Wikipedia, objects with these massive gravitational fields were first considered in the 18th century by John Michell and Pierre-Simon Laplace. Fast forward to 2019 - the first ever direct image of a black hole in the universe was made possible by extensive research and work of a group of astronomers of the Event Horizon Telescope (EHT). The EHT is a network of powerful, ground-based radio telescopes distributed around the world. PI’s 6-DOF alignment technology, integrated in many telescopes, is part of this success story. PI precision motion components (piezo mechanisms) were also involved, when the first merger of black holes was detected by the LIGO collaboration in February 2016, proving the existence of gravitational waves.
A total of eight observatories in Hawaii, Arizona, Mexico, Chile, Antarctica, and in the Spanish Sierra Nevada provided the raw data that was later processed into one single image. The principle behind combining feeds from multiple distant observatories is called Very Long Baseline Interferometry (VLBI) and basically interconnects the individual systems into one giant virtual telescope.