The sun's magnetic field is about to flip. Here's what to expect.

The sun is on the verge of a significant event: a magnetic field reversal. 

This phenomenon happens roughly every 11 years and marks an important stage in the solar cycle. The shift in polarity indicates the halfway point of solar maximum, the height of solar activity, and the beginning of the shift toward solar minimum. 

The last time the sun's magnetic field flipped was toward the end of 2013. But what causes this switch in polarity, and is it dangerous? Let's take a deep look at the sun's magnetic field reversal and investigate the effects it could have on Earth.

Related: Scientists discover the possible origin of the sun's magnetic field, and it's not where they thought it was

To understand the magnetic field's reversal, first, it's important to be familiar with the solar cycle. This approximately 11-year cycle of solar activity is driven by the sun's magnetic field and is indicated by the frequency and intensity of sunspots visible on the surface. The height of solar activity during a given solar cycle is known as solar maximum, and current estimates predict it will occur between late 2024 and early 2026.

But there is another very important, albeit lesser-known, cycle that encapsulates two 11-year solar cycles. Known as the Hale cycle, this magnetic cycle lasts approximately 22 years, through which the sun's magnetic field reverses and then reverts to its original state, Ryan French, a solar astrophysicist and Space.com contributing writer, told Space.com. 

During solar minimum, the sun's magnetic field is close to a dipole, with one north pole and one south pole, similar to Earth's magnetic field. But as we shift toward solar maximum, "the sun's magnetic field becomes more complex, without a clear north-south pole separation," French said. By the time solar maximum passes and solar minimum arrives, the sun has returned to a dipole, albeit with a flipped polarity.