Skip to main content

Monster 'El Gordo' | Space Wallpaper

Monster 'El Gordo' Galaxy
This space wallpaper is a Hubble Space Telescope image of ‘El Gordo,’ which is the nickname given to the most massive cluster of galaxies ever seen to exist when the universe was just half of its current age of 13.8 billion years. (Image credit: NASA, ESA, and J. Jee (University of California, Davis))

This space wallpaper is a Hubble Space Telescope image of the most massive cluster of galaxies ever seen to exist when the universe was just half of its current age of 13.8 billion years. The cluster, catalogued as ACT-CL J0102-4915 and nicknamed El Gordo, contains several hundred galaxies swarming around under the collective gravitational pull. The total mass of the cluster, as refined in new Hubble measurements, is estimated to weigh as much as 3 million billion stars like our Sun (about 3,000 times as massive as our own Milky Way galaxy) — though most of the mass is hidden away as dark matter. The location of the dark matter is mapped out in the blue overlay. Because dark matter doesn't emit any radiation, Hubble astronomers instead precisely measure how its gravity warps the images of far background galaxies like a funhouse mirror. This allowed them to come up with a mass estimate for the cluster.

Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: community@space.com.

Space.com Staff

Space.com is the premier source of space exploration, innovation and astronomy news, chronicling (and celebrating) humanity's ongoing expansion across the final frontier. Originally founded in 1999, Space.com is, and always has been, the passion of writers and editors who are space fans and also trained journalists. Our current news team consists of Editor-in-Chief Tariq Malik; Editor Hanneke Weitering, Senior Space Writer Mike Wall; Senior Writer Meghan Bartels; Senior Writer Chelsea Gohd, Senior Writer Tereza Pultarova and Staff Writer Alexander Cox. Senior Producer Steve Spaleta oversees our space videos, with Kim Hickock as our Reference Editor and Diana Whitcroft as our Social Media Editor.