NASA’s Chandra X-ray Observatory said that galaxy cluster MACS J0717 is one of the most complex and distorted galaxy clusters known. It’s the site of a collision between four four clusters, located about 5.4 billion light years away from Earth.
Galaxy clusters are enormous collections of hundreds or thousands of galaxies and vast reservoirs of hot gas embedded in massive clouds of dark matter. This images contains X-ray data from Chandra (blue), and optical light from Hubble (red, green, and blue).
The image is part of the “Frontier Fields” project, in which astronomers are studying half a dozen galaxy clusters, including MACS J0717.
Deborah Byrd created the EarthSky radio series in 1991 and EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.