Galaxies are streaming toward a mysterious point in space beyond the horizon of our visible universe. Earth is being pulled toward the same region. Astronomers call it the Great Attractor. The problem is that whatever is doing the pulling is invisible.

The Great Attractor lies in the Zone of Avoidance, a region of sky obscured by the dense dust and stars of the Milky Way's galactic plane . Observing it is like trying to see through a fog made of a trillion suns. What we can detect is its gravitational effect. Our Local Group of galaxies, including the Milky Way and Andromeda, is being dragged toward this anomaly at a speed of 600 kilometers per second .

The best current explanation is the Shapley Supercluster, a dense concentration of more than 8,000 galaxies located 650 million light-years away . But even the Shapley Supercluster may not be massive enough to account for the full gravitational pull. There may be something larger behind it—a supercluster of superclusters. Or there may be a flaw in our understanding of gravity itself.

Turn down the lights, put on your headphones, and press play because something is pulling Earth across the universe, and we cannot see what it is.