Some U.S. residents were lucky enough to witness the northern lights this week. The visual feast was actually the result of a pretty volatile phenomenon in the sun.

For much of last week, the sun was observed to have three significant coronal holes, NASA confirmed. The sun having holes in it might be enough to cause panic, but it's actually no big deal.

Coronary Holes On The Sun

These holes are common occurrences. Data from NASA revealed a vast region where the sun's magnetic field has opened up, creating a gap called the corona. They are open magnetic fields that cause high-speed solar wind to shoot outward into space, and when observed under ultraviolet light, they appear as dark regions. Images from the Solar Dynamics Observatory illustrate these dark patches in detail, showing where the solar wind originated. Current views of the sun are available on the observatory's website.

"The gaseous material is flowing from a wide hole in the sun's atmosphere, and could engulf our planet for several days," Spaceweather reports.

Auroras

When solar wind comes into contact with the Earth's magnetosphere, it can produce magnificent auroras, which are most commonly found in areas near the poles. The Space Weather Prediction Center classified the solar wind under the G1 minor geomagnetic storm watch on April 10. A similar event occurred last month that sent people into a panic frenzy, helped in large part by a number of publications who didn't do enough scientific research and spread misguided information instead.

The worst that a G1 minor geomagnetic storm can do is affect the planet's power grid systems and satellites, or degrade high-frequency radio waves. They're absolutely non-catastrophic, and they pose no great risk.

Solar winds can reach up to the G5 category, which is an extreme case. G1 storms, like the one discussed in this article, are extremely common. In fact, they happen once every two days.

This recent geomagnetic storm's auroras may have showed up to residents of Michigan, Maine, Montana, North Dakota, and Minnesota, according to the Space Weather Prediction Center.

"Coronal holes can develop at any time and location on the Sun, but are more common and persistent during the years around solar minimum. The more persistent coronal holes can sometimes last through several solar rotations (27-day periods)," says the Space Weather Prediction Center. "Coronal holes are most prevalent and stable at the solar north and south poles; but these polar holes can grow and expand to lower solar latitudes."