Aurora Borealis – wonderful lights
Auroras are dazzling displays of colored light that sometimes appear in the night sky. They can be seen in far northern and far southern regions. Auroras are named after Aurora, the ancient Roman goddess of the dawn.
An aurora constantly changes shape as the light moves across the sky. Its colors are determined by the different gases that give off the light.
The aurora borealis is visible only in the northern skies and is thus also known as the northern lights. The aurora australis occurs in the southern skies.
Auroras result from the interaction of Earth’s magnetic field with ionic gas particles, protons, and electrons streaming outward from the Sun. Solar storms result in magnetic disturbances that lead to coronal mass ejections of ionic charged particles in solar “winds.” As the magnetic particles pass Earth, the plasma streams interact with Earth’s magnetosphere. The magnetic interactions excite electron transitions that result in the emission of visible light.
The Valkyrior are warlike virgins, mounted upon horses and armed with helmets and spears. When they ride forth on their errand, their armour sheds a strange flickering light, which flashes up over the northern skies, making what men call the aurora borealis, or Northern Lights.
Bulfinch’s Mythology, 1855
– Unusually bright auroras are often seen as a good sign. According to legend, before the battle with the Crusaders on Lake Peipsi Alexander Nevsky’s army saw the northern lights, very bright for that area. The soldiers believed it was a sign from above and heavenly army was in a hurry to help them.
– The ancient Norse believed that the Northern Lights were the bridge for gods.
– Aurora can sing. Scientists have found that the collision of the solar wind with the Earth’s surface generates infrasound at a frequency of 7-13 Hz. It is impossible to hear the sound of the Northern Lights without special equipment.
– Auroras are more likely to occur in the fall and spring. They are observed in Norway, Finland, Iceland, Greenland and Russia (Murmansk, Norilsk, Petrozavodsk, St. Petersburg).
– Italian physicist and astronomer Galileo Galilei first described the northern lights in 1619.
– There are no two identical auroras, each has its own colors and patterns.
– Duration of auroras is from tens of minutes to several days.