- Auroras are caused by solar storms hitting Earth's magnetic field near the poles
- Solar wind particles collide with atmospheric gases, releasing light as auroras
- Alfven waves energize electrons, producing the bright bands known as auroral arcs
Auroras, the northern lights (aurora borealis) or southern lights (aurora australis), are breathtaking displays of colored light in the night sky. Auroras are caused by intense solar storms that hit Earth's magnetic field. The displays can come in various forms, such as bands, rays, patches and more. But ever wondered how the beautiful patterns are formed?
According to a new study published in Nature Communications, researchers have revealed the mystery behind a type of aurora called the auroral arcs.
While detailing the entire process, the study noted that the Sun emits a stream of charged particles, known as the solar wind, which includes electrons and protons.
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When the solar wind reaches Earth's magnetic field, it's funnelled towards the poles, where it collides with atmospheric gases like oxygen and nitrogen. These collisions excite the gas molecules, which then release energy as light, creating auroras.
These charged particles are then powered up by "Alfven waves," which is a special kind of plasma wave that travels along Earth's magnetic lines. It also functions like a "space battery".
The study noted that fast-moving electrons, aided by Alfven waves, hit atoms in the atmosphere. A light is released in towering bands, forming the Auroral arcs.
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"These combined observations provided different viewpoints over a long enough time to reveal more about the conditions in space that helped create the arc," NASA said in a statement.
"Similar particle acceleration has been observed by NASA's Juno spacecraft around Jupiter. Tian's team thinks Alfvén waves could also power auroral arcs at Jupiter and other worlds where auroras glow."
