Abell 98 is a system of galaxy clusters in the early stages of a collision. Astronomers have used data from the Chandrda X-ray Observatory to identify key structures in this system and search for some of the "normal" matter (not dark matter) missing from most observations of the local universe. Scientists have proposed that at least some of this unaccounted-for mass could be hidden in gigantic strands known as the "warm-hot intergalactic medium," or WHIM. The Chandra study has found evidence for the WHIM in Abell 98, shown here in images from Chandra and the WIYN telescope. Image credit: X-ray: NASA/CXC/CfA/A. Sarkar; Optical: NSF/NOIRLab/WIYN #NASAMarshall #Chandra #NASA #ChandraXrayObservatory #galaxy #galaxycluster