The Van Allen belts make up two separate zones full of trapped particle radiation that wrap around Earth inside its magnetic field.
These belts create big headaches for anyone building spacecraft or planning commercial space travel.
You’ll find the Van Allen radiation belts as two donut-shaped regions loaded with high-energy charged particles circling Earth.
Back in 1958, scientists found these belts after Explorer 1’s radiation detector measured particle levels that were just off the charts—way higher than anyone expected.
Earth’s magnetic field grabs these energetic particles and keeps them trapped, so they form concentrated radiation zones.
Inside the belts, you’ll find billions of protons, electrons, and other charged particles, all whizzing around at crazy speeds.
These radiation belts stretch from about 400 miles up to 36,000 miles above Earth.
Particles in these zones can fry unprotected electronics and threaten astronauts’ health if exposure lasts too long.
Space agencies design spacecraft with radiation shielding to survive the trip through these belts.
Commercial space companies have to factor in Van Allen belt radiation when they plan orbits and routes for their missions.
The inner Van Allen belt starts around 400 miles up and goes to about 6,000 miles above Earth.
High-energy protons make up most of this inner zone, and they show up when cosmic rays smack into Earth’s atmosphere.
The outer belt sits between about 8,000 and 36,000 miles altitude.
Solar wind particles get trapped by Earth’s magnetic field and build this outer radiation zone, which has mostly electrons.
There’s a gap between the two main belts where the particle count drops a lot.
Sometimes, during intense solar activity, scientists spot a temporary third belt forming in that region.
The belts follow Earth’s magnetic field lines and look thickest above the equator.
They thin out as you get closer to the magnetic poles, so you end up with that classic donut shape around the planet.
The Van Allen belts are packed with particles moving at nearly the speed of light.
All that high-energy particle radiation can punch right through spacecraft walls and wreck sensitive electronics.
Radiation levels in the belts jump around depending on what the Sun’s doing.
When solar storms hit, particle concentrations can spike, making it way riskier for spacecraft passing through.
The inner belt usually stays pretty steady over time.
The outer belt, though, is a lot more unpredictable—its particle count changes with space weather and shifts in the magnetic field.
Modern spacecraft rely on radiation-hardened electronics and aluminum shielding to get through the belts in one piece.
Commercial space vehicles try to zip through these zones as fast as possible, usually during launch or re-entry.
America’s first satellites made a huge discovery in 1958: the Van Allen radiation belts.
James Van Allen and his University of Iowa team pulled this off using simple Geiger counters on the Explorer 1 and Explorer 3 missions.
James Van Allen led the charge on this discovery at the University of Iowa.
He built the cosmic ray experiments that flew on the early Explorer satellites.
Van Allen’s team kept things simple but effective.
They hooked up Geiger counters to tiny tape recorders and sent them into space.
This let the instruments record data while orbiting and send it back to Earth.
Before all this, Van Allen had already been studying cosmic rays.
His background in particle physics really helped him figure out what all the weird readings from space meant.
Van Allen managed to show that Earth’s magnetic field traps high-energy particles in clear zones around the planet.
His grad students at Iowa helped build the instruments and sift through the mountain of data.
The whole team worked together to crack open a new understanding of Earth’s magnetic environment.
Explorer 1 blasted off from Cape Canaveral, Florida, on January 31, 1958.
That was America’s first satellite and the real start of the space age.
The spacecraft carried Van Allen’s cosmic ray experiment and a micrometeorite detector.
Explorer 1’s Geiger counter picked up radiation levels nobody expected.
Explorer 3 followed on March 26, 1958, and confirmed those wild results.
Both missions sent back key data about charged particles trapped by Earth’s magnetic field.
Key Mission Details:
Explorer 4 and Pioneer 3 joined in later that year, gathering even more info.
Thanks to these spacecraft, Van Allen figured out that Earth actually has two radiation belts, not just one.
The cosmic ray experiments uncovered intense radiation zones circling Earth.
Van Allen’s team saw that Earth’s magnetic field was trapping these particles, not just letting them drift in from space.
The inner belt is mostly protons.
The outer belt? Mostly electrons.
Scientists had guessed that Earth’s magnetic field could trap particles, but the Van Allen missions finally proved it.
Radiation Belt Composition:
This discovery flipped old ideas about Earth’s magnetic environment on their head.
Before 1958, a lot of folks thought trapped particles only showed up during magnetic storms.
Van Allen showed that permanent radiation belts always surround our planet.
Suddenly, there were new mysteries about space physics to chase.
People started calling them the Van Allen Belts, honoring the scientist who led the discovery.
That breakthrough set the stage for modern magnetospheric physics.
The Van Allen radiation belts form two separate, donut-shaped regions around Earth.
The inner belt holds mostly protons, while the outer belt contains mainly electrons and ions.
You’ll find the inner radiation belt between about 600 and 3,700 miles above Earth.
It’s packed with high-energy protons.
Protons make up around 95% of the particles here, and they carry a ton of energy—up to 400 million electron volts.
This belt doesn’t change much.
Solar storms barely touch it compared to the outer belt.
The inner belt hugs Earth’s magnetic field lines tightly, forming a narrow ring near the equator.
Key characteristics:
Spacecraft that pass through this belt take a beating from radiation exposure.
Proton bombardment can mess up electronics and put astronauts at risk.
The outer radiation belt stretches from about 8,000 to 37,000 miles above Earth.
Electrons rule this region, along with a mix of ions.
This belt changes a lot during space weather events.
Solar storms can boost the electron population by up to 100 times.
The outer belt holds particles at a bunch of different energy levels.
Some electrons zip around at nearly light speed, while others move slower.
Particle composition includes:
The solar wind is always reshaping this belt.
When things are quiet, it shrinks closer to Earth.
During active solar periods, the belt expands outward.
Satellites in geostationary orbit have to deal with the hazards of this radiation zone.
A lot of communication satellites operate right inside or near it.
Scientists found a third radiation belt in 2012 with NASA’s Van Allen Probes.
This belt pops up between the inner and outer belts when conditions are just right.
Solar storms can create the right magnetic field setup for this temporary belt to form.
It usually sticks around for a few weeks before fading away.
Formation process:
This belt is mostly electrons at medium energy levels.
Particles here don’t reach the crazy energies you see in the main belts.
The discovery forced scientists to rethink how radiation belts work.
Turns out, Earth’s magnetic environment is more complicated than anyone guessed.
The third belt shows that space weather can quickly change how particles get trapped around Earth.
It’s tough to predict or study since it doesn’t last long.
Earth’s magnetic field grabs charged particles from solar wind and cosmic rays, building the Van Allen belts.
Geomagnetic storms and solar activity can totally reshape these radiation zones, and the belts are always changing—sometimes slowly, sometimes in a flash.
Earth’s magnetosphere acts like a giant net, catching charged particles from several sources.
The main source is the solar wind, a constant stream of charged particles from the Sun that can hit speeds of 300 to 800 kilometers per second.
Cosmic ray interactions are another big source.
When cosmic rays slam into Earth’s upper atmosphere, they create secondary particles that get trapped by the magnetic field.
The inner belt is filled mostly with high-energy protons, with energies from tens of thousands up to hundreds of thousands of electron volts (keV).
These protons show up thanks to cosmic ray albedo neutron decay, where neutrons created by cosmic ray hits decay into protons and electrons.
The outer belt holds mainly energetic electrons, at energies from 0.1 to 10 million electron volts (MeV).
Solar wind interactions and local acceleration within the magnetosphere keep these electrons coming.
Earth’s magnetic field lines guide these particles in spirals.
Particles bounce between the poles and drift around Earth, building up stable radiation zones that can stick around for months or even years.
Geomagnetic storms bring the biggest changes to the Van Allen belts.
These storms hit when the solar wind suddenly changes, squeezing Earth’s magnetosphere and dumping new particles into the belts.
Coronal mass ejections from the Sun can trigger the strongest geomagnetic storms.
These blasts of charged particles can boost electron levels in the belts by 10 to 100 times in just a few hours.
During the biggest storms, scientists sometimes see temporary third radiation belts form.
The huge storm in May 2024—the strongest in twenty years—created a third belt that stuck around for months between the usual inner and outer zones.
Solar storms can either load up the belts with particles or, sometimes, wipe them out.
How much the radiation levels change depends on the storm’s strength.
Moderate storms usually pump up the outer belt, while really extreme storms can clear out the particles before the belts refill.
The South Atlantic Anomaly gets hit especially hard during storms.
Earth’s magnetic field is weaker there, so particles can dive deeper into the atmosphere, making it a dangerous spot for spacecraft and astronauts.
Van Allen belt intensity tends to follow some pretty predictable patterns, but there’s a lot of nuance over different time scales. The 11-year solar cycle drives big swings in radiation belt activity, with things really ramping up during solar maximum when the Sun gets stormy.
Seasonal variations show up too, thanks to Earth’s tilted magnetic axis and how it meets the solar wind. As Earth orbits the Sun, the belts face changing conditions—autumn often brings more activity than other seasons.
Short-term changes can happen surprisingly fast, sometimes within just hours or days during active periods. Electron populations in the outer belt might spike by a factor of a thousand during certain storms, only to fade back to normal over the next few weeks.
Particle loss processes constantly drain the belts. Particles escape when they smack into neutral atoms in the upper atmosphere or get scattered by electromagnetic waves out of their stable orbits.
Recent high-resolution measurements show the radiation belt dynamics are far more complicated than anyone guessed decades ago. With advanced instruments, scientists now spot rapid shifts in particle energy and see narrow energy bands forming inside each belt.
The inner belt stays fairly stable, especially compared to the outer belt, which just won’t sit still. Proton populations in the inner zone change slowly over months, but the outer belt’s electrons can swing wildly—sometimes within a single storm.
The Van Allen belts hold two main types of charged particles, and they each have their own energy levels and origins. The inner belt mostly traps energetic protons and some heavy ions, while the outer belt is really packed with high-energy electrons and positrons.
The inner Van Allen belt is mostly protons, with energies from 10 to 400 million electron volts (MeV). These protons end up trapped between about 1,000 and 6,000 miles above Earth’s surface.
Most inner belt protons come from cosmic ray albedo neutron decay (CRAND). When cosmic rays slam into Earth’s atmosphere, they create neutrons, which decay in around 15 minutes and release energetic protons that get stuck in the magnetic field.
Solar energetic protons also play a part in the inner belt. These particles, coming from solar flares and coronal mass ejections, make up the main source for protons under 50 MeV.
Heavy ions like helium and oxygen nuclei show up in the inner belt too, but there aren’t many compared to protons. Since these ions have bigger gyroradii, they don’t stick around as long before drifting out of the belts.
The outer Van Allen belt is dominated by relativistic electrons with energies between 100 thousand electron volts (keV) and several MeV. These electrons hang out from about 8,000 to 37,000 miles above the planet.
Unlike the inner belt, the outer belt’s electrons mostly come from outside. The magnetotail region stores electrons that start off in the solar wind. During magnetic storms, these electrons get shuttled inward and pushed to much higher energies.
Wave-particle interactions really matter for electron acceleration in the outer belt. Magnetospheric waves can give electrons a boost from hundreds of keV up to full MeV energies, leading to the wild swings in electron populations that researchers see.
The slot region between the belts is almost empty above 1 MeV. Scientists call this an “impenetrable barrier” because atmospheric loss rules out any real inward movement of high-energy electrons from the outer belt.
NASA has sent up a bunch of dedicated missions to study these radiation zones, using spacecraft designed to handle extreme radiation. The Van Allen Probes mission gave us the most detailed data yet, but earlier Pioneer missions really got the ball rolling on understanding these particle-filled regions.
NASA kicked off the Van Allen Probes mission in 2012 as part of the Living With a Star program. The mission started out as the Radiation Belt Storm Probes before getting renamed to honor James Van Allen.
The twin spacecraft flew in highly elliptical orbits through both belts, collecting data on particle motion and magnetic field interactions for over six years.
Key Mission Objectives:
The probes even caught a temporary third radiation belt forming during a particularly intense solar storm. That was a real surprise and showed just how dynamic these regions can get.
Scientists used advanced particle detectors and magnetometers on both spacecraft. The instruments measured electron and proton energies from low levels up to several million electron volts.
Pioneer 3 launched in December 1958, just months after Explorer 1 first found the belts. It didn’t make it to the moon, but it still managed to grab valuable radiation data during its short trip.
Explorer 4 went up in July 1958 with instruments built specifically to map the belt boundaries. That mission confirmed the two-belt structure that James Van Allen had predicted.
Later missions kept pushing our understanding further by trying out different orbits. Spacecraft like the Injun series in the 1960s studied how particles move in and out of the belts.
Notable Early Discoveries:
These early missions laid the groundwork for today’s space weather prediction systems that help keep astronauts and satellites safe.
The Van Allen belts present real radiation hazards for astronauts and mission planning. Anyone sending people beyond low Earth orbit has to come up with careful navigation strategies and protection for the crew.
Astronauts face two main radiation threats when passing through the Van Allen belts. High-energy protons in the inner belt can punch through spacecraft walls and damage human tissue, posing immediate risks during the crossing.
The outer belt’s energetic electrons create different problems. With enough exposure, these particles can cause skin burns or even eye damage. Astronauts might start feeling radiation sickness symptoms within just a few hours if they aren’t protected.
Acute radiation effects include:
Space agencies keep a close watch on astronaut radiation doses during missions. Each crew member wears a dosimeter to track exposure, and mission planners make sure time spent in high-radiation areas stays within safe limits.
The Apollo missions proved that people can survive belt crossings with the right shielding. Those crews only spent a short time in the radiation zones on their way to the Moon.
Spacecraft designers rely on several methods to shield crews from Van Allen belt radiation. Aluminum shields offer basic protection against lower-energy particles, but thicker shielding works better—though it adds weight and cost.
Trajectory planning makes a big difference. Flight paths are chosen to avoid the thickest parts of the belts whenever possible. Spacecraft cross quickly at the thinnest points, instead of lingering in the danger zones.
Key protection strategies include:
The Polaris Dawn mission recently tried out new radiation protection methods. The crew climbed to 1,400 kilometers, passing through the inner Van Allen belt, and their Dragon spacecraft used advanced shielding to keep exposure down.
Medical monitoring continues throughout any mission that crosses the belts. Flight surgeons keep an eye on astronaut health in real time, and emergency plans exist to bring crews home quickly if radiation spikes.
The International Space Station orbits well below the Van Allen belts, at about 400 kilometers up. This low orbit keeps the station and its crew safe from most belt radiation, though the ISS sometimes gets hit by extra radiation during solar storms.
Astronauts on the ISS still deal with space radiation from cosmic rays and solar particles, which are different risks than the Van Allen belts. Crews usually spend around six months on the station, with radiation exposure that’s considered manageable.
ISS radiation protection features:
The station’s orbit does cross the South Atlantic Anomaly, where particles from the belts dip closer to Earth. During those passes, sensitive equipment shuts down automatically and crew members move to safer parts of the station.
Research on the ISS helps scientists learn more about long-term radiation effects on humans. This data is essential for planning future trips to Mars or anywhere else that requires going through the Van Allen belts.
The Van Allen belts form some of the harshest radiation zones around Earth, and they can wreck satellite electronics or disrupt spacecraft operations. Modern satellites need special protection and toughened components to survive these high-energy environments.
Satellites in low-Earth orbit get hit constantly by charged particles trapped in the Van Allen belts. These high-energy protons and electrons cause three main types of damage to electronics.
Single event upsets happen when a radiation particle strikes a computer chip, causing glitches or even rebooting systems.
Total ionizing dose builds up over time as satellites soak in radiation. This gradually wears out semiconductor materials and shortens component lifespans.
Displacement damage occurs when particles knock atoms out of alignment in circuits, which can permanently reduce the sensitivity of cameras or sensors.
NASA has documented plenty of satellite failures caused by radiation exposure. Communication satellites seem to have the most trouble since they pass right through the outer belt. Solar storms can make things worse by ramping up particle densities.
Spacecraft designers use a mix of strategies to shield satellites from Van Allen belt radiation. Aluminum is the go-to shielding material for most satellites—it’s light and decent against lower-energy particles.
Tantalum offers even better shielding against high-energy radiation, but it’s heavy. Engineers sometimes use thin tantalum layers around critical electronics and stick with aluminum for the rest.
Radiation-hardened components are probably the most important protection. These chips and circuits are built to survive radiation levels thousands of times higher than standard electronics.
Redundant systems also help. Satellites carry backup computers, comms, and power supplies that kick in if the main ones fail.
NASA requires all spacecraft traveling through the belts to include these protection measures. The agency tests components in radiation chambers that mimic belt conditions before approving them for flight.
The Van Allen radiation belts serve as a natural barrier, deflecting some harmful particles from space. Still, these belts can only do so much when it comes to protecting us.
The Van Allen belts form a protective zone around Earth by catching charged particles from the solar wind and cosmic radiation.
Earth’s magnetic field grabs these high-energy particles and holds them in two main donut-shaped regions above the planet.
The inner belt starts around 620 miles up and stretches to about 3,700 miles above Earth.
This region mostly holds protons and some electrons that get trapped by the magnetic field lines.
The outer belt sits farther out and contains mainly electrons.
Its size and shape shift depending on solar activity and space weather.
Key protective functions include:
The belts and Earth’s magnetic field work together to steer away dangerous particles.
Cosmic ray experiments measuring radiation levels show that these belts cut down the amount of harmful particles that would otherwise strike Earth directly.
Solar storms can make the belts swell or shrink.
Sometimes, during these events, the outer belt pushes inward and fills the space between the two belts.
The Van Allen belts don’t block all space radiation.
They mainly trap charged particles, but some cosmic radiation still gets through.
Earth’s atmosphere actually serves as the main shield against most dangerous radiation.
The Van Allen belts act more like an extra filter than the main wall of defense.
Major limitations include:
The belts themselves create hazardous radiation zones that put spacecraft and astronauts at risk.
Satellites have to avoid certain orbital paths to dodge the intense radiation in these regions.
The atmosphere on the ground absorbs most dangerous particles.
The magnetic field deflects some cosmic rays, but a fair number still get through to Earth’s surface, though at lower levels.
Space missions need careful planning to keep exposure short when crossing these radiation zones.
The belts shield the surface but definitely complicate space travel and satellite operations.
Scientists keep making breakthroughs in understanding the Van Allen belts, thanks to advanced instruments and focused missions.
NASA’s Van Allen Probes uncovered unexpected complexity in these radiation zones, and new detection methods keep revealing hidden features.
The Van Allen Probes mission really changed what people thought about radiation belt dynamics between 2012 and 2019.
These twin spacecraft found that the belts behave much less predictably than most folks expected.
In 2012, researchers spotted something wild—a third radiation belt popped up between the usual inner and outer zones.
This new belt stayed stable and separate for several weeks before vanishing.
That discovery proved that space weather events can totally reshape Earth’s radiation environment.
Solar storms and changes in the magnetic field can make the belts grow, shrink, or even split apart.
Scientists discovered that particles inside the belts can get energized through several different mechanisms.
Local acceleration processes can boost particle energy to extreme levels in just hours or days.
That flies in the face of older theories that said particles only came from outside sources.
Recent solar activity brought another temporary third belt.
A major solar storm in May 2024 created a new radiation ring that could stick around for months or even years.
NASA’s Colorado Inner Radiation Belt Experiment detected this ring with advanced CubeSat technology.
NASA keeps up intensive Van Allen belt research using multiple missions and instruments.
Researchers published over 100 scientific papers in 2020 alone using Van Allen Probes data, often teaming up with partner missions worldwide.
New instruments use advanced detection techniques to spot previously invisible features deep inside the belts.
These tools can measure particle energies and magnetic field interactions with incredible precision.
Current research focuses on predictive modeling for space weather.
Learning how solar storms impact the belts helps protect robotic missions and future human flights.
Scientists really want to know how the new third belt will act.
If it sticks around, it could affect upcoming missions like Artemis 2, which plans to send astronauts through these radiation zones for the first time since 1972.
Research teams are working on better mathematical models to predict how the belts will change.
They combine satellite data with theoretical physics to forecast dangerous particle events days or weeks ahead.
When scientists discovered the Van Allen radiation belts, it marked the first big scientific breakthrough of the Space Age.
This changed how engineers design spacecraft and plan missions beyond Earth’s protective atmosphere.
The Van Allen belts present significant challenges for modern space missions and commercial operations.
Spacecraft traveling through these radiation zones have to use specially hardened electronics to avoid damage from high-energy particles.
Critical mission impacts include:
NASA’s Space Shuttle program timed launches to avoid peak radiation periods.
Modern commercial crew vehicles like SpaceX’s Dragon and Boeing’s Starliner use advanced shielding materials to keep passengers safe during trips through the inner belt.
The belts raise particular worries for lunar missions.
Spacecraft heading to the Moon pass through both radiation zones twice per trip.
Apollo missions relied on precise timing and trajectory planning to keep astronaut exposure as low as possible.
Space tourism companies now include radiation exposure in their safety plans.
Suborbital flights usually avoid the Van Allen belts by staying below 62 miles in altitude.
Explorer 1’s discovery of the Van Allen belts in 1958 kicked off space physics as a new scientific field.
James Van Allen’s instruments measured radiation levels 1,000 times higher than expected above 900 miles up.
This finding happened just months after the Soviet Union launched Sputnik and started the Space Age.
It revealed that space held unknown hazards that would affect every mission going forward.
Early on, scientists struggled to make sense of the radiation readings.
The Geiger counters on Explorer 1 would register intense radiation, then suddenly stop counting at higher altitudes where particles became overwhelming.
Modern research continues through:
The belts still attract plenty of research interest.
Scientists found a temporary third belt in 2012 that lasted only a month before it disappeared.
That showed the radiation environment changes more dynamically than anyone thought.
Current missions help protect satellite networks and support planning for Mars exploration.
The Van Allen belts create unique challenges for space missions.
These radiation zones affect everything from astronaut safety protocols to how spacecraft get built.
Astronauts cross the Van Allen belts as quickly as possible to keep radiation exposure low.
Mission planners figure out the best paths that spend the least time in dangerous areas.
Modern spacecraft include special radiation shielding in their hulls.
These materials absorb and deflect harmful particles before they reach the crew.
Real-time radiation monitors track exposure during the mission.
If radiation levels rise too high, these systems alert the crew right away.
SpaceX and other companies use automatic rebooting software to deal with equipment glitches caused by radiation.
This tech keeps critical systems running even when particles mess with electronics.
High-energy particles in the belts can damage human DNA at the cellular level.
That raises the long-term risk of cancer.
Short-term exposure can cause symptoms like nausea and fatigue.
Astronauts might feel these effects during or right after passing through the belts.
The central nervous system is especially at risk from radiation.
Heavy particles can affect thinking and decision-making.
Reproductive health also comes into play—there’s a chance for genetic damage that could impact future children.
Space agencies keep a close eye on these risks for all crew members.
The South Atlantic Anomaly stands out as the most important ground-level effect of the Van Allen belts.
This region stretches over parts of South America and the South Atlantic Ocean.
Here, the inner radiation belt dips much closer to Earth’s surface.
Satellites and spacecraft get hit with higher radiation levels when they pass over this spot.
The anomaly can affect the International Space Station’s operations during certain orbits.
Astronauts sometimes move to better-shielded parts of the station during these passes.
On the ground, people and equipment don’t see much direct effect from the belts.
The atmosphere does a pretty good job protecting everything at the surface.
Earth’s magnetic field traps charged particles from solar wind and cosmic rays.
These particles spiral along magnetic field lines and collect in certain regions.
The planet’s magnetosphere works like a giant magnetic bottle.
Particles get in near the poles but end up trapped in the equatorial regions where the field lines are strongest.
Solar activity directly affects belt intensity and structure.
More particles enter the magnetosphere during solar storms, strengthening the radiation zones.
Three belts exist at different altitudes, each with different types of particles.
Scientists have even spotted a temporary third belt that sometimes forms between the inner and outer zones.
The belts bring big engineering challenges for spacecraft electronics and human safety systems.
Engineers have to design equipment that can handle intense radiation.
Satellite operators consider belt effects when planning orbits and mission schedules.
Equipment wears out faster in high-radiation zones.
Future Mars missions depend on knowing how to navigate the belts.
Crews will spend extra time in these regions during Earth departure and return.
The belts also serve as a proving ground for deep space technologies.
Spacecraft that make it through the belts show they’re ready for interplanetary travel.
Commercial space tourism companies use belt data to keep passengers safe.
Knowing about radiation exposure helps set safe flight profiles for civilian travelers.
The inner Van Allen belt starts about 400 miles above Earth’s surface and stretches up to around 6,000 miles. You’ll mostly find high-energy protons here, all trapped by Earth’s magnetic field.
The outer radiation belt sits higher, from roughly 8,000 miles out to about 36,000 miles. This area mostly holds electrons and actually goes well past where geostationary satellites orbit.
Between these two main belts, there’s a slot region with fewer particles. Some spacecraft take advantage of this spot for safer passage.
The edges of the belts don’t stay in one place. Solar activity and changes in Earth’s magnetic field push the boundaries around, and during geomagnetic storms, the outer belt can swell far past its usual range.
