What Causes Northern Lights?

What Causes Northern Lights?

As of 2016, the percentage of tourists visiting Norway to watch the Northern Lights has increased by 378% since 2006. However, the real cause of this phenomenon was unknown until a few days ago, when a theory was proven at Iowa University. Let’s understand this theory and dive into this fascinating phenomena.

Crux of the Matter

Auroras
Auroras is a natural luminous phenomenon where natural light is displayed in the sky. They are mostly seen in the higher latitudes (near Arctic and Antarctic regions). They are called Aurora Borealis in Northern and Aurora Australis in Southern Hemisphere.

Features

  • Green is the most common colour in auroras and they produce faint sounds of claps, crackles and static sounds.
  • The name is derived from the name of the Roman goddess of the dawn, Aurora. As per the myth, she travelled from east to west to announce the arrival of the sun.
  • Boreas is the Greek term for the north wind
  • Auroras are visible from space. Planets like Jupiter, Saturn, Uranus and Neptune also have the same phenomenon.

Cause

  • They are caused by “powerful electromagnetic waves during geomagnetic storms,” according to a study by Iowa University. Geomagnetic storms on the Sun disturbs the magnetic field of Earth.
  • These disturbances produce electromagnetic waves, known as Alfven waves, which accelerate electrons and produce these lights.
  • This theory, called Landau damping, was proposed by Russian physicist Lev Landau in 1946.

In History

  • According to Scandinavian legends, these lights served as a gateway to Valhalla. In Norse mythology, Valhalla is believed to be the place where martyred soldiers spent their afterlife.
  • It is considered a bad omen in European Culture. Blazed red lights were visible over the British Isles a week before the French Revolution started.
  • In Japan, a child born during the northern lights is believed to be blessed with good looks, intellect and good luck.

Curiopedia
  • The term Aurora Borealis was coined by Galileo Galilei in 1619 A.D. It was named after Aurora, the Roman goddess of morning.
  • The International Space Station is at around the same elevation as the Northern Lights. The astronauts in the ISS can see the lights from the side.