Particles emerging from even the lowest energy collisions of small deuterons with large heavy nuclei at the Relativistic Heavy Ion Collider (RHIC)—a U.S. Department of Energy Office of Science User Facility for nuclear physics research at DOE’s Brookhaven National Laboratory—exhibit behavior scientists associate with the formation of a soup of quarks and gluons, the fundamental building blocks of nearly all visible matter. These results from RHIC’s PHENIX experiment suggest that these small-scale collisions might be producing tiny, short-lived specks of matter that mimics what the early universe was like nearly 14 billion years ago, just after the Big Bang.