Approaching the Universe’s origins

This intriguing image from the NASA/ESA Hubble Space Telescope shows a massive galaxy cluster called PSZ2 G138.61-10.84, about six billion light-years away. Galaxies are not randomly distributed in space, but rather aggregated in groups, clusters and superclusters . The latter span over hundreds of millions of light-years and contain billions of galaxies.

Our own galaxy, for example, is part of the Local Group , which in turn is part of the giant Laniakea Supercluster . It was thanks to Hubble that we were able to study massive galactic superstructures such as the Hercules-Corona Borealis Great Wall ; a giant galaxy cluster that contains billions of galaxies and extends 10 billion light-years across — making it the biggest known structure in the Universe.

This image was taken by Hubble’s Advanced Camera for Surveys and Wide-Field Camera 3 as part of an observing programme called RELICS (Reionization Lensing Cluster Survey) . RELICS imaged 41 massive galaxy clusters with the aim of finding the brightest distant galaxies for the forthcoming NASA/ESA/CSA James Webb Space Telescope (JWST) to study.