Dark energy is the placeholder name scientists have given to the unknown force causing the universe to expand faster and faster over time. But some recent cosmic clues have been chipping away at the leading theory for this phenomenon, which could eventually mean humanity will have to rethink our understanding of the universe.

The Dark Energy Spectroscopic Instrument, or DESI, is an international effort involving more than 900 researchers. The project has produced gargantuan sky maps and helped reveal some of the universe’s largest structures,