ALT This animated GIF shows what we might see if we looked at two black holes through the disk of gas that is swirling around them. The gas is bright orange close to the black holes and fades out to shades of purple farther out. As the animation proceeds, one black hole moves in front of the other, from our point of view. When one black hole is in front of the other, the orange light is magnified in an arc that then encircles the black hole. These effects look like a fun house mirror. The image is watermarked with “Simulation” and “Credit: NASA's Goddard Space Flight Center/Scott Noble; simulation data, d'Ascoli et al. 2018.”