Keck Cosmic Web Imager offers best glimpse yet of the filamentous network that connects galaxies

Like rivers feeding oceans, streams of gas nourish galaxies throughout the cosmos. But these streams, which make up a part of the so-called cosmic web, are very faint and hard to see. While astronomers have known about the cosmic web for decades, and even glimpsed the glow of its filaments around bright cosmic objects called quasars, they have not directly imaged the extended structure in the darkest portions of space—until now.