Astronomy: Aurora Borealis

Aurora Borealis

An aurora (pl. aurorae or auroras) is a natural light display in Earth’s upper atmosphere caused by charged particles from the Sun colliding with atoms in the atmosphere.

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Source: Wikipedia (CC BY-SA)

Aurora Borealis An aurora (pl. aurorae or auroras) is a natural light display in Earth’s upper atmosphere caused by charged particles from the Sun colliding with atoms in the atmosphere. These collisions excite oxygen and nitrogen, which then emit light of different colors such as green, red, and purple.

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Source: Internal

Why Aurora Borealis matters: Understanding our cosmic neighbourhood helps us learn about planetary formation, the conditions for life, and ultimately our place in the universe. When observed in high-latitude regions they are called polar lights and aurora polaris. In the Arctic they are called northern lights (aurora borealis); in the Antarctic, the terms southern lights (aurora australis) are used. Auroras display dynamic patterns of radiant light that appear as curtains, rays, spirals or dynamic flickers covering the entire sky. Auroras are the result of disturbances in the Earth's magnetosphere caused by enhanced speeds of 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. Other planets in the Solar System, brown dwarfs, comets, and some natural satellites also host auroras.

Commentary

Source: Internal

Deep dive: Aurora Borealis In the Arctic they are called northern lights (aurora borealis); in the Antarctic, the terms southern lights (aurora australis) are used. Auroras display dynamic patterns of radiant light that appear as curtains, rays, spirals or dynamic flickers covering the entire sky. Auroras are the result of disturbances in the Earth's magnetosphere caused by enhanced speeds of 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. Other planets in the Solar System, brown dwarfs, comets, and some natural satellites also host auroras. Source: https://en.wikipedia.org/wiki/Aurora (Wikipedia, CC BY-SA)