Free Astronomy Magazine May-June 2026

MAY-JUNE 2026 T he Bullet Cluster is made up of two galaxy clusters that are colliding, one moving through the other, about 3.7 billion light-years away in the constellation Carina. These galaxy clusters act as gravitational lenses, magnifying the light of background galaxies. This phenomenon makes the Bullet Cluster a compelling piece of evidence supporting the existence of dark matter. [CTIO/NOIRLab/DOE/NSF/AURA. Image Processing: T.A. Rector (University of Alaska Anchor- age/NSF NOIRLab) & M. Zamani (NSF NOIRLab)] different from what was predicted. When DES added the most recent data, that gap widened, but not yet to the point of certainty that the standard model of cos- mology is incorrect. The difference persisted even when DES combined their data with those of other experi- ments. Next, DES will combine this work with the most recent constraints from other dark energy experiments to in- vestigate alternative gravity and dark energy models.