Earth Grew New Radiation Belt

Based on reports from NASA’s Colorado Inner Radiation Belt Experiment (CIRBE) satellite, Earth developed two unprecedented radiation belts following a powerful geomagnetic storm in May 2024, including a unique proton-dominated belt that may still persist, challenging our understanding of magnetospheric dynamics and raising concerns for space travel and satellite operations.

Formation of New Radiation Belts

The May 2024 geomagnetic storm, the most powerful in 21 years, triggered the formation of two extraordinary radiation belts sandwiched between Earth’s permanent Van Allen belts12. These new belts consisted of:

• An electron belt with 1.3–5 MeV electrons at L=2.5–3.5

• A proton belt containing 6.8–20 MeV protons at L=23

The electron belt demonstrated unusual longevity, persisting for over three months instead of the typical four-week duration4. This unprecedented event not only caused widespread aurora displays and GPS disruptions but also challenged existing theories about radiation belt dynamics, particularly regarding the formation and stability of temporary belts

Unique Proton Belt Characteristics

Unlike typical temporary radiation belts composed solely of electrons, the proton belt discovered after the May 2024 solar storm exhibited remarkable stability12. This unique feature challenges existing models of radiation belt dynamics and may have long-lasting implications for our understanding of magnetospheric processes3. The proton belt’s unusual composition and persistence suggest that extreme solar events can create more complex and enduring structures in Earth’s near-space environment than previously thought4.

CIRBE Satellite and REPTile-2

The detection of the new radiation belts was made possible by the fortuitous reactivation of NASA’s Colorado Inner Radiation Belt Experiment (CIRBE) satellite in June 2024, after it had fallen silent due to a technical malfunction in mid-April1. The satellite carries the advanced Relativistic Electron Proton Telescope integrated little experiment-2 (REPTile-2), a miniaturized instrument featuring:

• 60 energy channels for electron measurements (0.25–6 MeV)

• Advanced guard rings to prevent contamination

• Pulse Height Analysis (PHA) for high-energy resolution23

This sophisticated equipment allowed for detailed measurements of the newly formed radiation belts, providing unprecedented insights into their composition and behavior4. The REPTile-2’s capabilities were crucial in distinguishing the unique characteristics of the proton belt, a discovery that has significant implications for our understanding of Earth’s magnetospheric response to extreme solar events5.

Implications for Space Technology

The discovery of these new radiation belts has significant implications for space technology and operations. Spacecraft launching into geostationary orbits now face potential risks from these unexpected high-energy particle environments, necessitating reevaluation of shielding and orbital strategies12. For astronauts, these belts represent additional hazards during space missions, particularly for those venturing beyond low Earth orbit3. The longevity of the electron belt and the unusual stability of the proton belt also raise concerns about long-term effects on satellite operations and space-based communications systems4. These findings underscore the need for continued monitoring and improved modeling of Earth’s magnetosphere to better predict and mitigate the impacts of future extreme solar events on our increasingly space-dependent technologies.