Electrical interference makes atomic clocks unsuited for dark matter detection, but nuclear clocks don’t have that problem, and could provide a resolution some 100,000 times better than what we currently have. Once considered an unusable byproduct of the U.S. nuclear program, thorium-229—an isotope of the silvery-white metal, thorium—could become central to humanity’s search for dark matter. Today’s most accurate clocks (atomic clocks) rely on the oscillations of electrons between two quantum states to keep time. Proposed nuclear clocks, which use the nuclei of an atom, are far less impacted by these disturbances. Thorium-229, however, is special because its resonance frequency is low enough to be excited by modern laser technology, theoretically making a nuclear clock possible.