Published on Feb 8, 2020

Galaxy Aurora Background Images

License Info: Creative Commons 4.0 BY-NC
Advertisement

An aurora sometimes referred to as polar lights, northern lights (aurora borealis), or southern lights (aurora australis), is a natural light display in the Earth’s sky, predominantly seen in the high-latitude regions (around the Arctic and Antarctic).

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.

Advertisement

Most auroras occur in a band known as the “auroral zone”, which is typically 3° to 6° wide in latitude and between 10° and 20° from the geomagnetic poles at all local times (or longitudes), most clearly seen at night against a dark sky. A region that currently displays an aurora is called the “auroral oval”, a band displaced towards the night side of the Earth. Early evidence for a geomagnetic connection comes from the statistics of auroral observations. Elias Loomis (1860), and later Hermann Fritz (1881) and Sophus Tromholt (1881) in more detail, established that the aurora appeared mainly in the auroral zone. Day-to-day positions of the auroral ovals are posted on the Internet

Download free Galaxy Aurora Background images gallery

Advertisement

Matched Content:


Related Images:

Leave a Comment