Auroras With Strange Behavior Captured in the Night Sky; What Caused Them to Pulsate and Tear Apart?

Strange spots of light were seen floating in the night sky after a solar storm to the amazement of sky-gazers in Europe.

A Look at a Strange Phenomenon

The event on April 23 resulted from the impact of a coronal mass ejection (CME) from the Sun into the Earth's atmosphere. This phenomenon causes a severe G4-class geomagnetic storm. The auroras seen by the viewers were commonly due to geomagnetic storm triggered by CME. However, this particular sight changed from regular auroras into strange blobs.

One of the residents who saw the event was Heiko Ulbricht from Saxony, Germany. According to him, the auroras started tearing apart and pulsating, creating single spots floating in the night sky. Knowing that auroras do not usually act like this, Ulbricht was amazed, and his pulse still raced hours later.

This phenomenon is called proton aurora, a light display resulting from the Earth's invisible planetary rings composed of ring currents. They are made of electrically charged ions flowing around the Earth in a gigantic ring of electrical current. There are instances when solar plasma from a CME smashes into the magnetic field and atmosphere of the Earth during a strong geomagnetic storm. As a result, the protons present in this invisible ring system go down and reach our planet. A secondary rai of electrons then reacts with the gases in the Earth's atmosphere, resulting in auroras that behave strangely.

Aside from the unusual pattern, different colors were also observed by sky-gazers, such as green, red, and blue. The various colors displayed during this event resulted from electrons that relax from different energy levels of oxygen atoms and nitrogen atoms, as explained by Brett Carter, an associate professor in space science at Australia's Royal Melbourne Institute of Technology (RMIT) University.

Meanwhile, the pulsating behavior of proton auroras resulted from plasma activity in the ring current of the Earth. They commonly appear during sunset as the protons are pushed by the magnetosphere towards the dusk side of the Earth. Despite the explanations from the experts, the behavior shown by auroras as they tear themselves apart in a dramatic way remains a mystery.

During the same geomagnetic storm that caused this strange event, regular auroras were observed more south of the planet due to storm strength. On the other hand, the northern lights were also seen in California, Wyoming, and Nevada.

How is Auroras Formed?

An aurora is a display of light observed in the regions of the Earth near the north pole and south pole. It is called aurora borealis in the northern hemisphere and aurora australis in the southern hemisphere.

The activity on the surface of the Sun causes this spectacular event. During solar storms, the surface of the Sun releases immense clouds of electrically charged particles known as solar wind. As they travel millions of miles away from the Sun, they sometimes collide with the atmosphere of the Earth.

Around 98% of these charged particles are deflected by our planet's magnetic field. However, a small amount of these ions is trapped in the region of the atmosphere called the ionosphere.

The wavy patterns of auroras that resemble a curtain are due to the lines of force in the earth's magnetic field. Another distinct feature of the auroras is the presence of various light colors. During an aurora display, nitrogen, and oxygen, two of the most abundant gases in our atmosphere, give off their characteristic color as they get heated.

Check out more news and information on Auroras in Science Times.