The beautiful warning: the science behind aurora and the risk it signals

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My first Aurora Australis

Like many people who have relocated to Australia, I had seen aurora pictures all over social media and wished to see them with my own eyes. So I joined Facebook groups like Aurora Australis and Aurora Hunting. But with my busy schedule, I either forgot about it completely or was too tired to go hunting.

That changed when I accidentally saw an aurora while walking back to my place on 26 May 2026. The view was not even that great, but I could not take my eyes off the purple hue in the sky. I later realised that what I saw was not actually an aurora (AAMI aurora). Even though I was fooled, it made me wonder about the science behind these lights.

What is Aurora?

Auroras, commonly known as the northern lights (aurora borealis) and southern lights (aurora australis), occurs when charged particles from the Sun collide with gases in Earth’s atmosphere, igniting glowing curtains of light that sway across the night sky (Aurora - NASA Science).

NASA/Lacey Young

But the same solar activity that paints the sky can also disrupt the technology we depend on. To understand both the beauty and the risk, we first have to understand the Sun. The Sun runs in cycles, and we are now in Cycle 25.

It simply starts with the Sun.

To track the aurora, we first have to understand the Sun and its activity. The Sun runs in cycles, and reached the peak of Cycle 25 in 2024.

When sunspot numbers are high, they produce more particles, resulting in more particles hitting Earth’s atmosphere, leading to more frequent and more intense auroras.

However, the sunspot number is only one of many parameters used to track the aurora. Although the most recent peak was in October 2024, the Gannon Storm, the most extreme geomagnetic storm named by NOAA, occurred in May 2024. This historic storm made the aurora visible from the ground in many parts of the world.

What happens when the Sun’s blast reaches Earth?

During the Gannon Storm, a fast gust of solar wind reached Earth and shook its magnetic field within about an hour. Two things decide how big a storm it causes: how fast that gust is travelling (the solar wind speed), and how strong the magnetic field it carries is (ScalarB).

A faster solar wind hits harder. And the stronger its magnetic field (ScalarB), the more of its energy can pour into Earth’s own magnetic field. This incoming energy disturbs Earth’s magnetic field and makes it shake.

The shaking is measured with the Kp index, where 9 is the maximum. The more energy that pours in, the harder the field shakes, and the higher the Kp climbs. A higher Kp means the aurora extends further from the pole toward lower latitudes (SWS - Aurora), allowing more people to see it. On 10-11 May 2024, the Kp index reached 8 to 9, the top of the scale.

But the same geomagnetic shaking that lit up the sky can also induce unwanted currents in power lines and pipelines, and disturb the satellites we rely on for GPS and communications (CSIRO Expert Commentary, 2024).

How widely this event was felt?

This interactive map shows where people across southern Australia and New Zealand reported seeing the aurora with the naked eye during the Gannon Storm. Because the storm was so intense, the aurora even reached the Australian mainland.

Observers also reported the aurora in a range of different hues. Hover over a point to see the colours each person saw.

Can we still see an Aurora in 2026?

We are now past the peak of Solar Cycle 25, so the chance of a display like May 2024 is lower than before, but not zero. CSIRO scientists note that major storms can still strike well after the cycle’s peak, so comparable events are likely over the next few years (CSIRO Expert Commentary, 2024).

That is the part worth sitting with. The next big storm might once again gift us a sky full of colour, or it might test the power grids, satellites, and GPS we now depend on. May 2024 was a gentle reminder of a force we still cannot predict more than about an hour in advance.

So keep an eye on the aurora tracking apps, and on the sky. But it is worth remembering that the same lights we chase are also a warning we are only beginning to take seriously.