A vital gap in Earth’s space weather defense system has finally been closed. After nearly two decades without monitoring in a key region of the globe, scientists have reactivated a solar cosmic ray detection station atop Haleakalā, a dormant volcano on the Hawaiian island of Maui. This marks a major step in restoring the planet’s global space weather monitoring network crucial for forecasting solar storms that can disrupt power grids, GPS, and satellite systems.
For 19 years, a giant hole stretched across the equator of the Pacific from Thailand to Mexico City leaving scientists blind to important data as powerful, high-energy particles from solar flares bombarded Earth. Now, with the return of a neutron monitor on Haleakalā, that blind spot has been filled.
Standing at 10,023 feet, the Haleakalā summit offers prime conditions for detecting neutrons uncharged particles generated by solar activity that impact Earth’s atmosphere and technology. Its high elevation and position near the equator ensure maximum sun exposure year-round, placing it directly in the path of solar particles.
“We really have to have the whole Earth peppered with neutron monitors,” explains Jim Ryan, a University of New Hampshire (UNH) professor emeritus of physics and the driving force behind the project. “Bringing the neutron monitor on Haleakalā back online should make a dramatic improvement in our space weather modeling efforts.”
The project, funded by the National Science Foundation and led by the University of Hawai‘i in collaboration with UNH, has brought together veteran researchers and young scientists alike.
Ph.D. students Malcolm Colson and Andrew Kuhlman, along with research engineer Jason Legere, played a hands-on role—building the monitor, rewriting its data software, and traveling to Maui to install and calibrate it.
“Being able to say we were here for the whole process of getting it off the ground building something with my own hands it’s a good feeling,” says Colson. Kuhlman agrees: “It’s really cool to create an instrument for space science and actually see it in action.”
Neutron monitors are one of the oldest tools in space physics but remain among the most reliable. They provide continuous, long-term data on solar activity, essential for understanding how the Sun’s outbursts affect Earth. UNH has deep roots in this field, having installed a monitor on Mount Washington over 60 years ago, which is still operational today.
Ryan, who guided Colson and Kuhlman through the project, recalls that the 19-year monitoring gap on Haleakalā was due to a combination of funding and logistical challenges. “But what matters now is that we’re back,” he says. “We’re moving the science forward.”
Looking over the newly installed equipment at the Haleakalā summit, Ryan reflects on his decades of work with neutron monitors and the return of this technology to the global system. “What’s old is new again,” he says, smiling. “It’s all coming back around.”
With the Haleakalā station back online, the world is once again better equipped to track and respond to the Sun powerful and sometimes dangerous impulses.