While axions are not currently a proposed direct explanation for dark matter, they could’ve set the stage for the creation of dark matter in the early stages of our universe.

Scientists are undeniably excited by this third possibility, though they’re also urging restraint due to the other potential explanations.

“I’m trying to be calm here, but it’s hard not to be hyperbolic,” Neal Weiner, a particle theorist at New York University, who was not involved in the research, told The New York Times. “If this is real, calling it a game changer would be an understatement.”