The Sun’s Activity 2024: Loops & Spots & Prominences, OH MY!
Mind Bending | July 10, 2024
By Dr. Teri Gee, Director, Barlow Planetarium
Last month, the northern lights were visible as far south as Florida. That’s not very northern, but it’s all because of our Sun. Right now, our Sun is in an active pattern, heading toward a solar maximum sometime this year or next.
So what does that mean?
In a solar maximum, the Sun has a lot of activity happening.
In a solar minimum, the Sun is pretty calm.
What causes the Sun to become active?
It has to do with the Sun’s magnetic field. You might know that the Earth has a magnetic field. It protects us from cosmic rays from space and energy from the Sun. Without it, we probably wouldn’t have an atmosphere. Well, the Sun has a magnetic field, too, but because the Sun is made of gas, and not rocks, its magnetic field does weird things.
Every 11 years, the magnetic poles trade places. During that cycle, the magnetic field gets tangled up in itself – like stretching a rubber band around and around an orange. When it gets pulled tight, the rubber band snaps. On the Sun, the poles flip near the solar maximum and the Sun basically resets itself. That reset is a solar minimum.
As we near a solar maximum, we can tell by the appearance of different structures on the Sun. The more of them we see, the closer we are to maximum.
Identifying activity
One structure is a sunspot on the surface. A sunspot is a place where the magnetic field gets tangled up and the temperature goes down which makes it look darker.
Other structures are prominences and loops that often appear during the active part of the solar cycle and can extend thousands of miles off the surface of the Sun.
The most violent activity on the Sun are coronal mass ejections (CME) when the magnetic field causes the ejection of large amounts of matter and energy into space. When the Earth is lined up with the CME, we can end up with northern lights. The stronger the CME, the more intense the aurora.
If you have special solar glasses (like the ones you used to watch the solar eclipse), you can sometimes see sunspots with your own eyes! If so, keep in mind, those sunspots are bigger than our entire planet!
The active cycle on the Sun is giving us multiple chances to see the northern lights. If you get to see them, remember that it’s thanks to our local star! Once the magnetic field resets in the next few months, we’ll see very little activity for a few years until the active cycle begins yet again.