The average number of visible dark patches on the sun's surface in August was higher than any other month since September 2001. The final count was more than twice as high as experts initially predicted it would be.
The number of black spots peppering the sun's surface in August was the highest for almost 23 years, new data shows. The latest sunspot count was more than twice as high as initial forecasts predicted and is another clear sign that the sun's explosive peak, or solar maximum, is likely well underway — and will be far more active than scientists initially thought.
Sunspots are regions of the sun's surface where surges of electromagnetic radiation break through the star's magnetic field, creating relatively cool patches that appear black to us thanks to an optical illusion. Along with the size and frequency of solar flares and coronal mass ejections, sunspot numbers indicate the progress of the sun's roughly 11-year solar cycle.
During the sun's least active phase, or solar minimum, there are very few or occasionally no sunspots. For example, in late 2019, shortly before the start of the current solar cycle (Solar Cycle 25), there were 40 consecutive days with no visible sunspots. But as the sun's magnetic field gets entangled with itself and weakens, sunspot numbers quickly climb before peaking during solar maximum. During this active phase, the sun's magnetic field eventually snaps and completely flips, which triggers a falling-off period of solar activity and a decrease in sunspots until the whole cycle restarts.