The first image of a black hole

Scientific developments

First Very Long Baseline Observations performed by ALMA

ALMA, the Atacama Large Millimeter/submillimeter Array, has successfully combined its immense collecting area and sensitivity with that of APEX (Atacama Pathfinder Experiment) to create a new, single instrument through a process known as Very Long Baseline Interferometry (VLBI).

Larger telescopes can make sharper observations, and interferometry allows multiple telescopes to act like a single telescope as large as the separation — or baseline — between them. In VLBI, data from two independent telescopes are combined to form a virtual telescope that spans the geographic distance between them — potentially up to the diameter of the Earth — yielding extraordinary magnifying power.

— Official Announcement

The first image of a black hole

On April 10, 2019, the first image ever captured of a black hole was presented to the public. But what were the events that lead to this discovery?