Aurora

An aurora[lower-alpha 1] (plural: auroras or aurorae[lower-alpha 2]), also commonly known as the polar lights,[lower-alpha 3] is a natural light display in Earth's sky, predominantly seen in high-latitude regions (around the Arctic and Antarctic). Auroras display dynamic patterns of brilliant lights that appear as curtains, rays, spirals, or dynamic flickers covering the entire sky.[3]

Images of auroras from around the world, including those with rarer red and blue lights
Aurora australis seen from the ISS, 2017.[1]

Auroras are the result of disturbances in the magnetosphere caused by the solar wind. Major disturbances result from enhancements in the speed of the solar wind from coronal holes and coronal mass ejections. These disturbances alter the trajectories of charged particles in the magnetospheric plasma. These particles, mainly electrons and protons, precipitate into the upper atmosphere (thermosphere/exosphere). The resulting ionization and excitation of atmospheric constituents emit light of varying colour and complexity. The form of the aurora, occurring within bands around both polar regions, is also dependent on the amount of acceleration imparted to the precipitating particles.

Most of the planets in the Solar System, some natural satellites, brown dwarfs, and even comets also host auroras.


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This article uses material from the Wikipedia article Aurora, and is written by contributors. Text is available under a CC BY-SA 4.0 International License; additional terms may apply. Images, videos and audio are available under their respective licenses.