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Insights from the May 2024 Solar Storm: New Particle Belts Around Earth

In May 2024, Earth experienced one of the most significant solar storms in the past two decades, unleashing a barrage of high-energy particles that impacted the planet for several days. This powerful event not only created stunning auroras visible in the night sky but also caused temporary disruptions in GPS communications.

Remarkably, the storm led to the formation of two new temporary belts of energetic particles encircling Earth. The findings surrounding these belts, aided by a resurrected small NASA satellite, shed light on the potential impacts of future solar storms on our technological infrastructure.

These newly formed belts are situated between the existing permanent structures known as the Van Allen Belts, which are shaped like concentric rings above Earth’s equator. These permanent belts harbor a mixture of high-energy electrons and protons, confined by Earth’s magnetic field. The particles within can pose risks to spacecraft and astronauts navigating through them; consequently, gaining a deeper understanding of their behavior is essential for the safety of space missions.

A study detailing the discovery, conducted using data from NASA’s Colorado Inner Radiation Belt Experiment (CIRBE) satellite, was published on February 6, 2025, in the Journal of Geophysical Research: Space Physics. The study emphasizes the significance of the new belts for spacecraft en route to geostationary orbits, as these vessels must traverse the Van Allen Belts multiple times during their ascent.

While temporary particle belts have been recorded post-solar storms in the past, the latest findings are noteworthy because the newly identified innermost belt contains energetic protons, in addition to the usual electrons. This distinct particle makeup is likely attributed to the specific characteristics of the solar storm itself.

Lead author Xinlin Li, a professor at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado Boulder, expressed excitement over the findings: “When we compared the data from before and after the storm, I said, ‘Wow, this is something really new.’ This is really stunning.”

The longevity of the new belts is particularly remarkable. Previous temporary belts typically lasted around four weeks; however, the latest electron-dominated belt persisted for over three months. Furthermore, the belt containing protons is expected to remain for an extended period due to its position in a stable region, which shields it from the various physical processes that can expel particles from their orbits. This belt may still be present today.

According to David Sibeck, former mission scientist for NASA’s Van Allen Probes, “These are really high-energy electrons and protons that have found their way into Earth’s inner magnetic environment. Some might stay in this place for a very long time.”

The persistence of these belts will likely be influenced by subsequent solar storms. Major storms can impart enough energy to dislodge particles from the belts, causing them to escape into space or fall back to Earth. For instance, storms at the end of June reduced the new electron belt’s size, while another in August nearly eliminated the remainder of it, though a small population of high-energy electrons managed to survive.

The critical discoveries were facilitated by NASA’s CIRBE CubeSat, a compact satellite the size of a shoebox, which orbited near the planet’s magnetic poles from April 2023 to October 2024. CIRBE was equipped with a specialized instrument known as the Relativistic Electron Proton Telescope integrated little experiment-2 (REPTile-2), a miniaturized version of a device that had previously identified temporary electron belts during NASA’s Van Allen Probes mission in 2013.

After a year of operation, the CubeSat encountered a malfunction on April 15, 2024, causing it to go silent. Although scientists were unable to collect data during the May solar storm, they managed to gather preliminary information from other spacecraft. Fortunately, the CIRBE satellite resumed operations on June 15, allowing researchers to capture high-resolution data that was unattainable through other instruments and provided crucial insights into the new particle belts.

While the CubeSat’s mission offered significant opportunities, it was not without challenges. The solar storm contributed to increased atmospheric drag on the CubeSat, hastening its orbital decay, ultimately leading to its deorbit in October 2024. However, the data collected before its demise substantiates the mission’s success.

“We are very proud that our very small CubeSat made such a discovery,” Li stated.

CIRBE was developed by LASP at the University of Colorado Boulder and launched as part of NASA’s CubeSat Launch Initiative (CSLI). The mission received support from NASA’s Heliophysics Flight Opportunities for Research & Technology (H-FORT) program.

Source
science.nasa.gov