Facts about Aurora

16 facts about Aurora

Northern light that has delighted people for centuries

Auroras can be different. Sometimes it is bright and dancing, shimmering with different colors, sometimes it appears still. It has always fascinated people all over the world. The inhabitants of countries where it appears regularly have been trying to understand this light phenomenon for centuries. They created various theories that became stories and entered the canon of folk tales.
The aurora is an inseparable element of the polar regions.
It occurs in high latitudes, mainly beyond the Arctic Circle. It also happens, however, that under favorable conditions, it can be observed around the 50th parallel.
There are two types of auroras: northern - Aurora Borealis, and southern - Aurora Australis.
Auroras are caused by magnetic storms in the Sun.
Huge amounts of high-energy charged particles (mainly protons and electrons) are then ejected from the surface of the Sun. They form the so-called solar wind. The accelerated particles of the solar wind are intercepted by the Earth's magnetic field and interact with the ionized atmosphere at an altitude of about 100 km.
The particles that make up the solar wind, upon contact with the Earth's magnetic field, spiral along the lines of this field and collide near the magnetic poles with molecules of nitrogen and oxygen, etc.
They arouse them, and these, returning to the ground state, radiate energy in the form of light quanta.
The color of the aurora depends on the height at which the atoms are colliding, and the type of atom.
If the collision is with nitrogen, we see the color purple and maroon. Collision with oxygen gives green and red colors. Yellow is the result of nitrogen and oxygen mixing. Lighter gases (hydrogen and helium) give a blue and purple color.
To the naked eye, we see the Aurora Borealis and Aurora Australis lights as greenish and white. Full colors can only be seen in the photos.
This is because, in low light, the eye registers light with rods that are not color sensitive but respond only to light.
The greatest intensity of auroras occurs at maximum solar activity - this happens every eleven years.
Then you can observe auroras also in Europe.
Auroras take many shapes. They can appear in the form of colored rays, streaks, ribbons, curtains, crowns, arcs, and others.
The Aurora Borealis in the northern hemisphere is visible between September 21 and March 21, between 6 p.m. and 1 a.m. when it is dark outside.
The range of the region in Northern Europe includes the Kola Peninsula in Russia and the territory of three Nordic countries: Finland, Sweden, and Norway.
The Aurora Australis appears within the Earth's south magnetic pole.
The phenomenon can be observed in Tasmania, a mountainous island about 300 km south of the Australian coast, as well as in New Zealand. However, the most visible aurora is in Antarctica, where there is almost no artificial lighting.