For the first time, scientists have spotted something wobbling around the black hole at the core of our galaxy. Their measurements suggest that this stuff—perhaps made of blobs of plasma—is spinning not far from the innermost orbit allowed by the laws of physics. If so, this affords astronomers their closest look yet at the funhouse-mirrored space-time that surrounds a black hole. And in time, additional observations will indicate whether those known laws of physics truly describe what’s going on at the edge of where space-time breaks down.
Astronomers already knew that the Milky Way hosts a central black hole, weighing some four million suns. From Earth, this black hole is a dense, tiny thing in the constellation Sagittarius, only as big on the sky as a strawberry seed in Los Angeles when viewed from New York. But interstellar gas glows as it swirls into the black hole, marking the dark heart of the galaxy with a single, faint point of infrared light in astronomical images. Astronomers call it Sagittarius A* (pronounced “A-star”).