Freiberg vs Aurora

Informations

Freiberg is a university and former mining town in the Free State of Saxony, Germany. It is a so-called Große Kreisstadt (large county town) and the administrative centre of Mittelsachsen district. Its historic town centre has been placed under heritage conservation and is a chosen site for the proposed UNESCO World Heritage Site known as the Ore Mountain Mining Region. Until 1969, the town was dominated for around 800 years by the mining and smelting industries.

In recent decades it has restructured into a high technology site in the fields of semiconductor manufacture and solar technology, part of Silicon Saxony. It is home of the oldest university of mining and metallurgy in the world - the Freiberg University of Mining and Technology.

Source: Wikipedia

Informations

An aurora (plural: auroras or aurorae), sometimes referred to as polar lights (aurora polaris), northern lights (aurora borealis), or southern lights (aurora australis), is a natural light display in the Earth's sky, predominantly seen in 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.

Source: Wikipedia