Solar Maximum and Visible Auroras

The sun is currently entering the most energetic phase of its 11-year cycle. Known as the solar maximum, this period is characterized by intense solar flares and Coronal Mass Ejections (CMEs) that are responsible for recent spectacular displays of the Northern and Southern Lights. While the aurora borealis is a bucket-list item for many, this peak in solar activity is pushing the aurora australis (Southern Lights) further north, creating rare viewing opportunities in places that usually never see them.

Understanding the Solar Maximum

To understand why the skies are glowing red and green, you have to look at the magnetic lifecycle of the sun. The sun operates on a roughly 11-year cycle known as the solar cycle. We are currently in Solar Cycle 25, which began in December 2019.

During the “solar minimum,” the sun is quiet, with few sunspots and relatively calm weather. As we approach the “solar maximum,” the sun’s magnetic field becomes tangled and unstable. This instability leads to a dramatic increase in sunspots. These dark, cooler areas on the solar surface are actually the launchpads for massive energy releases.

According to the Space Weather Prediction Center (SWPC) operated by NOAA, Solar Cycle 25 has outperformed initial forecasts. While original predictions suggested a mild cycle, the sun has been far more active. Experts now predict the peak of this activity will continue through late 2024 and into 2025. This means the window for seeing auroras at lower latitudes is wide open right now.

How Solar Flares Create Auroras

The light show begins with a violent event on the sun. When magnetic energy builds up around sunspots, it can release suddenly in two forms:

1. Solar Flares: These are flashes of light and high-energy radiation. They travel at the speed of light and reach Earth in about eight minutes. They can cause radio blackouts but do not directly cause auroras.
2. Coronal Mass Ejections (CMEs): This is the key player for auroras. A CME is a massive cloud of magnetized plasma hurled into space. If Earth happens to be in the path of this cloud, the plasma slams into our planet’s magnetic field (magnetosphere).

This collision causes a geomagnetic storm. The charged particles from the sun travel down Earth’s magnetic field lines toward the poles. When these particles strike atoms in our atmosphere, they excite the gases, causing them to glow.

• Oxygen: Produces the most common green colors at lower altitudes (up to 150 miles) and rare red colors at very high altitudes (above 150 miles).
• Nitrogen: Produces blue or purple light.

The Expansion of the Auroral Oval

Under normal conditions, the “auroral oval” (the ring of light around the magnetic poles) stays tight against the Arctic and Antarctic circles. This is why you typically have to travel to Fairbanks, Alaska, or Tromsø, Norway, to see the lights.

However, during the intense storms we are seeing in this solar maximum, that oval expands significantly toward the equator.

The snippet you read highlighted “rare southern aurora sightings.” This refers to the Aurora Australis. Usually, this phenomenon is reserved for Antarctica and the surrounding ocean. But during extreme geomagnetic storms—like the historic G5 storm witnessed in May 2024—the southern lights became visible in populated areas.

Residents in Tasmania, the South Island of New Zealand, and parts of southern Australia captured vivid displays. In extreme cases, the southern lights have been photographed as far north as Queensland, Australia, and parts of South Africa and Chile. This expansion is directly tied to the Kp index, a number from 0 to 9 that measures geomagnetic activity.

• Kp 0-2: Quiet. Auroras only visible at the poles.
• Kp 5: Minor storm. Visible in Tasmania or Scotland.
• Kp 8-9: Extreme storm. The oval expands deep into mid-latitudes (like the continental US or mainland Australia).

Recent Activity and What to Expect in 2025

The sun has been producing X-class flares, which are the most powerful category of solar flares. In recent months, active sunspot regions (such as the massive region AR3664) have rotated across the sun, firing multiple CMEs toward Earth.

Because we are at or near the peak of the cycle, these events are clustered. A single sunspot group can fire four or five CMEs in a week. If these merge on their way to Earth, they create what scientists call a “Cannibal CME,” which packs a much harder punch and results in brighter, longer-lasting auroras.

For those hoping to catch a glimpse of the Southern Lights, the next 12 to 18 months offer the best statistical chance in over a decade. The NOAA SWPC provides 3-day forecasts that can alert you when a CME is incoming.

Photography vs. The Naked Eye

It is important to manage expectations regarding what you will see. The photos you see online often look neon bright. This is because modern camera sensors are much more sensitive to low light and color than the human eye.

When the aurora is weak, it may look like a faint, grey pillar or cloud to the naked eye. However, during the intense storms associated with this solar maximum, the colors become visible without a camera.

If you are hunting for the lights, specifically the southern variety, keep these tips in mind:

• Look South: If you are in Australia, New Zealand, or South America, you need a clear view of the southern horizon.
• Escape Light Pollution: You need true darkness. Even the glow of a small town can wash out the aurora. Use a website like Dark Site Finder to locate an area with low light pollution.
• Use Your Phone: If you cannot see color, put your phone camera in “Night Mode” and take a 3-second exposure. The phone might reveal pinks and greens that your eyes are missing.

Frequently Asked Questions

Is the solar maximum dangerous to humans on Earth? No. Earth’s atmosphere and magnetic field protect us from the radiation. However, intense solar storms can impact technology. They can disrupt GPS signals, radio communications, and create voltage irregularities in power grids.

When exactly will the solar maximum end? Solar cycles are hard to predict down to the month, but the current peak activity is expected to taper off gradually. High activity should continue through 2025, with the cycle winding down toward a solar minimum around 2030.

Why are red auroras rarer than green ones? Red auroras occur at much higher altitudes (over 180 miles) where the oxygen density is low. It takes more energy to excite these high-altitude atoms. Therefore, you usually only see distinct red colors during strong geomagnetic storms (Kp 7 or higher).

Where is the best place to see the rare southern aurora? Tasmania (Australia) and the South Island of New Zealand are the most accessible locations with the highest probability of sightings. Southern Chile and Argentina are also excellent viewing spots when the weather cooperates.