The Sun is constantly changing and goes through different cycles where it has more or less activity. The main cycle that experts track is an approximately 11-year cycle, which goes from a solar maximum to the solar minimum. As the names imply, the maximum is when there is a high amount of activity, including lots of sunspots, flares, and coronal mass ejections. The minimum is when these events are comparatively very rare.

On Earth, we may notice things like more frequent and more powerful Aurora Borealis during the solar maximum as well as additional interference with electronic devices.

In addition to this cycle, however, there is what is known as the Centennial Gleissberg Cycle, which occurs approximately every seven to eight solar cycles (so closer to every 80-90 years than the 100 years the term Centennial would suggest). During the Gleissberg cycle, the magnetic fields that are located within the solar atmosphere change. This has far-reaching impacts, and they are actually measured by looking at the area of space around our own planet.

Specifically, experts will look at the Van Allen belts, which are regions of radiation in the magnetic field of the Earth. There are two such belts, a smaller one that is around 1000-6000 kilometers (600-3700 miles) wide and a larger one that is 13,000-60,000 kilometers (8100-37300 miles) wide.

A recent study published in the journal Space Weather found that it is likely that the Centennial Gleissberg Cycle is in the process of switching. This is measured by looking at the level of protons that are in the Van Allen belts. The proton flux that takes place in the inner (smaller) belt is lower when the Sun is more active.

Measurements of the proton flux over the region known as the South Atlantic Anomaly show that this cycle has occurred, and it is likely that the sun will be getting more active over the next several solar cycles. The maximum will likely occur sometime around 30 years from now.

The last time this occurred, astronomers were able to gather some information thanks to technology and other equipment that was not around in the past. The fact that our technology has advanced dramatically since then, and that we can now better predict this activity, means that scientists will be able to gather massive amounts of information.

The researchers don’t just have to wait around for three decades to learn more about the sun, though. Tracking its activity throughout a full cycle will help them to understand the sun and how it affects us here on Earth better than ever before.

Who knew the Sun had such dramatic cycles?

If you thought that was interesting, you might like to read about a second giant hole has opened up on the sun’s surface. Here’s what it means.