Observable Universe

The sphere of space from which light has had time to reach us since the Big Bang — about 46.5 billion light-years in comoving radius, containing an estimated two trillion galaxies. Its edge is a horizon of our viewpoint, not a physical boundary: the universe continues beyond it, and every observer sees their own observable universe centered on themselves. On the largest scales its contents become nearly uniform, the endpoint of the cosmic web's hierarchy of structure.