Around the horizon of a black hole, an edge of the universe, light is captured, spun into orbit by the black hole’s powerful gravitational pull. Lying within the orange donut in the famous first image of a black hole, this “photon ring” would be a prize to measure—it would reveal the nature of spacetime itself, directly, near the horizon. Indeed, the shape of this pure ring of light tells everything about the black hole. With the stakes this high, a new collaboration—physicists, astronomers, engineers from around the world—has formed to loft a spacecraft that capture the photon ring. We are at the beginning of what is probably a ten-year effort—this is a film about the start of that adventure.

A film by Peter Galison, Michael Johnson, and Chyld King