Aurora: a Sun-Kissed Earth Spectacle

Aurorae are lights in the sky whose colors vary from red, green, yellow, pink, purple and blue.

Above: NASA astronaut Scott Kelly captured photographs and video of auroras from the International Space Station on June 22, 2015.

Modern physics explains the nature of aurorae as when electromagnetic particles enter the Earth's atmosphere and ionize it, resulting in breathtaking rays of light in the sky.

Aurorae are also called the northern and southern lights because they occur mostly in the Arctic and the Antarctic regions. Earth’s inner core attracts charged space particles like a giant magnet, and this impact appears in the Poles better than anywhere else.

Above: Rays of light from an "Aurora Borealis" illuminate the sky over Stockholm City at 23:05 local time (21:05 GMT) Thursday night, April 6, 2000.

The Earth’s atmosphere is heterogeneous, and charged solar wind particles “paint” it in different colors: oxygen “flares” with red and green, and nitrogen produces the violet light.

Above: The northern lights dance over the Knik River near Palmer, Alaska, Wednesday, November 29, 2006.

People often perceived an aurora as a good sky-sign. Russian warriors believed that an aurora betokened a victory.

The Alaskan Inuits, who have been observing northern lights for centuries, believe that those lights are coming from a sky palace where the souls of their deceased forefathers live. When a hunter’s soul wants to see its homeland on the Earth, it opens a window in the palace, and people see the light.

Ancient Norwegians believed that an aurora is a bridge used by gods to descend to the Earth. Another legend says that aurorae are a reflection of star light on Valkyries’ shields.

The aurora can sing! The collision of solar wind particles with the Earth results in a sound with a frequency of 7-13 Hertz. But humans cannot hear it, because the ear is capable of hearing sounds with a frequency of 16 Hertz and higher.

An aurora’s form is usually a stripe or a spot. Sometimes a stripe is blurred, and a spot becomes more distinct, depending on the frequency.

An aurora occurs when the sun emits energy and flares. Therefore an aurora is the moment when the Sun touches our planet.

Aurorae also take place on other planets. Lights have been observed on Saturn, Jupiter, Uranus and Neptune.

Aurorae can be created artificially. Soviet and French scientists produced an aurora in 1975 to study the ionosphere and the magnetic field of the Earth.