High up in the sky, the sun looks the same day in and day out.
But looking closer and with the right equipment, you can see areas of the sun showing signs of activity: sunspots.
Sunspots are cooler regions on the surface of the sun where temperatures can be nearly 2,000 degrees less than the surrounding surface. They are believed to be caused by the sun's magnetic field.
Right now, the largest sunspot of 2017 is traveling across the sun's surface. It's part of a group so large, that 11 Earths could fit inside!
Finding sunspots like these will be harder in the next few years because of the sun's solar cycle, a change in the sun's activity that happens about every 11 years.
At this point in the cycle, we're going to see fewer sunspots - and holes will open in the sun's atmosphere. If other factors fall into place, we may have a chance to see northern lights.
It could also disrupt communications and navigation systems, like the power grid and GPS.