Astrakhan vs Aurora

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Astrakhan (Russian: Астрахань, IPA: [ˈastrəxənʲ]), is the largest city and administrative centre of Astrakhan Oblast in Southern Russia. The city lies on two banks of the Volga, in the upper part of the Volga Delta, on eleven islands of the Caspian Depression, 60 miles (100 km) from the Caspian Sea, with a population of over 529,739 residents. At an elevation of 28 meters (92 ft) below sea level, it is the lowest city in Russia. Astrakhan was formerly the capital of the Khanate of Astrakhan (a remnant of the Golden Horde), and was located on the higher right bank of the Volga, 7 miles (11 km) from the present-day city.

Situated on caravan and water routes, it developed from a village into a large trading centre, before being conquered by Timur in 1395 and captured by Ivan the Terrible (who believed it to be the site of the Fountain of Youth) in 1556. In 1558 it was moved to its present site. The oldest economic and cultural center of the Lower Volga, it is often called the southernmost outpost of Russia, and the Caspian capital. The city is a member of the Eurasian Regional Office of the World Organization "United Cities and Local Governments". The great ethnic diversity of its population gives a varied character to Astrakhan.

Source: Wikipedia

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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