We’ve seen indirect evidence for decades. Now it’s time for the Event Horizon Telescope to stare one in the eyes.
Scientists have discovered plenty of black holes, but the evidence has always been indirect… But by enlisting an array of telescopes, the Event Horizon Telescope will utilize very long baseline array interferometry to measure perturbations in gas around Sagittarius A (Sag A), the black hole at the center of our galaxy. In very long baseline array interferometry, the arrival of photons from Sag A will come at different times, with each telescope measuring the same event. By reconstructing what each telescope sees, a picture can emerge of whatever is happening at the center of our galaxy.