The photo highlighted by NASA this Wednesday (19) shows a spectacular and colorful aurora that shone in the sky of Lapland, Finland. It was the result (beautiful, by the way) of a geomagnetic storm, caused by the activity of the Sun.
Before the aurora appeared in the sky, the Sun had released a coronal mass ejection (CME). Because the CME particles “missed” Earth, scientists didn’t expect the geomagnetic storm to create auroras as colorful and vast as the one pictured below:
That night, the aurora borealis was so bright that it was captured in detail in the photo. The colors of the phenomenon indicate the reactions that occur between the electrons emitted by the Sun and the elements in the Earth’s atmosphere, such as oxygen and nitrogen.
Typically, the aurora borealis occurs in regions located at high latitudes; but, this time, there were reports of auroras observed further south, as in the sky of New Mexico, in the United States.
What are geomagnetic storms?
To understand geomagnetic storms, it’s important to remember, first, that the Earth is surrounded by the magnetosphere. This is a region formed by the magnetic field of our planet, which works like a bubble that protects us against most of the particles coming from the Sun.
When a coronal mass ejection occurs or some other phenomenon that releases large amounts of electrically charged particles, these events cause disturbances in the magnetosphere upon reaching Earth. This is how a geomagnetic storm arises.
Geomagnetic storms are accompanied by a series of effects, such as heating of the ionosphere and upper atmosphere. The increase in temperature can increase the density and distribution of gases in the upper atmospheric layers, intensifying the drag on satellites in low Earth orbit. With that, they can perform re-entries earlier than expected, as happened with Starlink satellites last year.
Source: ETC
