Researchers investigating an exploratory drilling site in northern Minnesota have uncovered something few expected to find beneath forests and wetlands. Deep underground, trapped within ancient rock formations, lies a measurable concentration of a rare helium isotope that scientists have long associated with the Moon rather than Earth.
The discovery was made at the Topaz Project near the town of Babbitt, where test wells revealed the presence of helium-3, an isotope prized for its scientific and technological uses. Laboratory analysis showed concentrations of roughly 14.5 parts per billion, a figure that closely mirrors measurements taken from lunar samples returned during NASA’s Apollo missions. For context, helium-3 is vanishingly rare in Earth’s atmosphere and only appears in trace amounts in most known gas fields.
The analyses were led by Dr Peter Barry of Woods Hole Oceanographic Institution, with samples independently verified by laboratories in Ohio and Massachusetts. Across multiple gas samples, researchers observed a consistent ratio of helium-3 to helium-4, suggesting the isotope originates from a single, stable geological source rather than contamination or surface processes.
Helium-3 differs from the more common helium-4 by having one fewer neutron, a subtle change that gives it unusual properties. It is highly effective at capturing neutrons, making it essential for radiation detectors and nuclear monitoring equipment. It is also used in ultra-low temperature refrigeration systems, which are critical for quantum computing and advanced physics research. Because global supply largely depends on the decay of tritium from aging nuclear stockpiles, helium-3 has remained scarce and expensive, commanding prices measured in millions of dollars per kilogram.
Geologists believe Minnesota’s ancient, uranium-rich bedrock has been generating helium for billions of years. Heat and long-standing faults allow the gas to migrate upward, where nitrogen-rich carrier gases transport it into trapped reservoirs sealed by impermeable rock layers. Unlike conventional natural gas fields, the Topaz site contains little to no hydrocarbons, reducing some environmental risks but raising new regulatory questions in a state with no commercial history of gas production.
The project is being advanced by Pulsar Helium, which says even modest production could ease supply pressures for research institutions and emerging technologies. State regulators, tribal authorities, and local communities are now weighing the implications, balancing environmental concerns against potential economic benefits.
While large-scale production remains uncertain, the find challenges assumptions about where rare strategic materials can be found. If further drilling confirms recoverable volumes, a resource once thought exclusive to lunar soil may turn out to be quietly waiting beneath the American Midwest.
This article contains information from a press release by Pulsar Helium Inc.
