Built from the first three all-sky surveys done by the eROSITA telescope aboard the Spectrum-Roentgen-Gamma (SRG) mission, DR2 provides the most sensitive and comprehensive catalogue of the X-ray sky currently available to the public. Nearly two million sourcesThe main DR2 catalogue contains close to two million X-ray sources detected in the 0.2–2.3 kiloelectronvolt (keV) band across the western half of the sky. Together, these two catalogues capture the diversity of the X-ray universe, from nearby stars to distant active galactic nuclei (AGNs) and massive galaxy clusters. “We’re observing a supermassive galaxy cluster and the process by which matter accretes along cosmic filaments,” Dietl reveals. “Our working group in Bonn led the analysis of—and was the first to measure—the faint X-ray emission in the outer reaches of this galaxy cluster.”