Grain-sized magnet tests ultraheavy dark matter, expanding search to ten million mass units
Rice University researchers levitated a grain-sized magnet above a cryogenic superconducting trap to search for ultraheavy dark matter. The September 2026 results found no signal, but extended the searchable dark-matter mass range by about seven orders of magnitude (roughly ten million times heavier than earlier levitated-particle experiments). The approach demonstrates that an ultraquiet, long-duration mechanical sensor can probe candidates well beyond prior limits, with plans for longer measurements and multiple sensors to further extend the reach.