Using the 10-m Keck I Telescope at the W. M. Keck Observatory in Hawaii, an international group of astronomers has discovered a distant quasar illuminating a giant gaseous nebula, about 2 million light-years across, within the network of filaments connecting galaxies in a cosmic web. This image shows the nebula (cyan) extending across 2 million light-years that was discovered around the quasar UM 287 (center of the image). Image credit: S. Cantalupo...