Shining Green Lights of the Aurora Australis Today’s Image of the Day comes thanks to the NASA Earth Observatory and features a look at the shining green lights of the aurora australis.
The aurora australis, also known as the southern lights, occurs after charged particles from space are swept up by the solar wind.
Solar plasma applies pressure, which stretches the magnetic field, especially on the night side of Earth. This causes particles stuck in the magnetic field to become energized.
This energy is released and transferred to oxygen and nitrogen molecules in the atmosphere. These gases emit photons, which are small bursts of energy that manifest in the form of light.
This image was taken by astronaut Jack Fischer on board the International Space Station while passing over the Great Australian Bight.
Auroras are the result of disturbances in the magnetosphere caused by solar wind. These disturbances are sometimes strong enough to alter the trajectories of charged particles in both solar wind and 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 color 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. Precipitating protons generally produce optical emissions as incident hydrogen atoms after gaining electrons from the atmosphere. Proton auroras are usually observed at lower latitudes
Source: NASA Earth Observatory