Solar Maximum Arrives: Expect More Auroras and Grid Risks

NASA and the National Oceanic and Atmospheric Administration (NOAA) have officially announced that the sun has reached its solar maximum. This peak period in the sun’s magnetic activity cycle means we are currently experiencing the highest number of sunspots and solar storms of the decade. While this brings the promise of spectacular northern lights in unusual locations, it also introduces genuine risks to global power grids, satellite networks, and GPS systems.

Understanding Solar Cycle 25

The sun operates on roughly an 11-year cycle. During this time, it moves from a quiet period known as the solar minimum to a period of intense activity called the solar maximum. We are currently in the peak of Solar Cycle 25, which began in December 2019.

On October 15, 2024, the Solar Cycle 25 Prediction Panel confirmed that the solar maximum is underway. Unlike a single day of peak activity, the maximum is a phase that can last for several years. Experts anticipate this phase will continue through 2025 and potentially into early 2026.

Why This Cycle is Different

Initial predictions for Solar Cycle 25 suggested it would be a weak cycle, similar to the previous one (Cycle 24). However, the sun has outperformed these forecasts.

  • Sunspot Counts: The number of sunspots is significantly higher than predicted. Sunspots are dark, cooler areas on the solar surface where magnetic fields are particularly strong. These spots are the launching pads for solar flares.
  • Magnetic Complexity: The magnetic field is more tangled than anticipated, leading to more frequent X-class flares, which are the most intense type of solar explosion.

The Northern Lights Are Moving South

For most people, the most visible impact of the solar maximum is the aurora borealis (Northern Lights) and aurora australis (Southern Lights). During solar maximum, the “auroral oval” expands toward the equator. This allows people who live far from the poles to witness displays usually reserved for the Arctic Circle.

This was demonstrated vividly during the historic geomagnetic storm of May 10-12, 2024. This event was classified as a G5 (Extreme) storm, the highest rating on NOAA’s scale. It was the strongest storm to hit Earth since the Halloween Storms of 2003.

During the May event, auroras were documented in locations including:

  • Florida and Texas in the United States.
  • Northern India (Ladakh region).
  • Puerto Rico and parts of Mexico.
  • Southern Europe, including Italy and Spain.

With the solar maximum now officially here, scientists expect similar opportunities throughout 2025. You do not need to book a flight to Iceland to see the lights; you simply need to monitor space weather alerts for G4 or G5 storm watches.

Risks to Technology and Infrastructure

While auroras are beautiful, the energy behind them poses a threat to modern infrastructure. When the sun ejects a massive cloud of plasma, known as a Coronal Mass Ejection (CME), it slams into Earth’s magnetosphere. This interaction creates Geomagnetic Induced Currents (GICs) that travel through the ground.

The Power Grid

The biggest concern for utility companies is the electrical grid. GICs can flow up ground wires and into massive high-voltage transformers. These currents can overheat the transformer cores, causing permanent damage or tripping safety relays that lead to blackouts.

  • Historical Context: In March 1989, a geomagnetic storm caused the collapse of the Hydro-Québec power grid in Canada. Six million people lost power for nine hours.
  • Current Mitigation: Modern grid operators receive warnings from NOAA’s Space Weather Prediction Center (SWPC). When a storm is imminent, they can reroute power loads or put capacitors in place to block the excess current. However, an extreme “Carrington-class” event (named after the massive 1859 storm) could still overwhelm defenses.

Satellites and Low Earth Orbit

The solar maximum creates a difficult environment for satellites. Increased solar ultraviolet emission heats Earth’s upper atmosphere, causing it to expand. This expansion increases the density of the air at Low Earth Orbit (LEO) altitudes, creating drag on satellites.

In February 2022, SpaceX lost 40 out of 49 newly launched Starlink satellites. A minor geomagnetic storm caused the atmosphere to warm and density to increase, creating drag that pulled the satellites out of orbit before they could reach their operational altitude.

GPS and Aviation

Solar flares ionize the upper layers of the atmosphere. This messes with the transmission of high-frequency radio signals.

  • Aviation: Airlines flying over the poles often have to reroute during solar storms because they lose contact with High Frequency (HF) radio communications. This leads to longer flights and higher fuel costs.
  • Agriculture and Drilling: Precision GPS is vital for modern farming and oil drilling. During intense solar activity, GPS accuracy can degrade by tens of meters, halting operations that require centimeter-level precision.

How Geomagnetic Storms Are Measured

To understand the risks, it is helpful to know the scales scientists use. NOAA uses the G-Scale to communicate severity to the public.

  1. G1 (Minor): Weak power grid fluctuations. Auroras visible in Maine or Michigan.
  2. G2 (Moderate): Voltage alarms may trigger at high-latitude power systems. Auroras visible in New York or Idaho.
  3. G3 (Strong): Voltage corrections required. False alarms on some protection devices. GPS issues likely. Auroras visible in Illinois or Oregon.
  4. G4 (Severe): Widespread voltage control problems. Satellite navigation degraded for hours. Auroras visible in Alabama or Northern California.
  5. G5 (Extreme): Complete grid collapse possible. Satellite navigation out for days. Auroras visible in Florida and Texas.

Preparing for the Peak

The solar maximum is a natural part of our star’s life. While the risks are real, agencies like NOAA and the US Air Force work 24⁄7 to monitor the sun.

For the average person, preparation involves awareness.

  • Download an App: Apps like Aurora Reach, SpaceWeatherLive, or My Aurora Forecast provide real-time data on the Kp index (a measure of geomagnetic activity).
  • Follow the SWPC: The NOAA Space Weather Prediction Center website offers a 3-day forecast. Look for “Geomagnetic Storm Watches.”
  • Backup Power: While a total grid collapse is unlikely, local interruptions can happen. Standard emergency preparedness, such as having flashlights, batteries, and non-perishable food, is sufficient for most solar scenarios.

This solar maximum is proving to be stronger than scientists first thought. We are currently living through the most active solar period in over 20 years, offering a mix of technological challenges and unprecedented natural beauty.

Frequently Asked Questions

How long will the solar maximum last? The solar maximum is not a single day. It is a phase that can last for two to three years. Scientists expect high activity levels to persist throughout 2025 and potentially into 2026 before the sun begins to wind down toward the next solar minimum.

Is solar activity dangerous to humans on the ground? No. Earth’s atmosphere and magnetic field protect human bodies from the radiation caused by solar flares and CMEs. You are safe walking outside during a solar storm. The danger is strictly limited to technology, electrical grids, and astronauts in space who are outside the protective atmosphere.

Can a solar storm destroy the internet? While a “internet apocalypse” is a popular theory online, it is unlikely. Fiber optic cables (the backbone of the internet) are not affected by geomagnetic currents because they carry light, not electricity. However, the repeaters that boost signals along undersea cables are electrically powered and could be vulnerable. A massive storm might cause regional disruptions, but a total global internet wipeout is improbable.

When is the best time to see the aurora? The best time is usually within a few hours of midnight. However, during a strong G4 or G5 storm, auroras can be visible as soon as the sky gets dark. Keep an eye on the Kp index; usually, a Kp of 7 or higher is required for mid-latitude visibility.