THE LIGHTS WE ALL KNOW AND LOVE- AURORA BOREALIS
Written by Shradha Vinodh
Fun fact, In the Norse mythology, the aurora was a fire bridge to the sky built by the gods. We all have seen pictures and have imagined just standing there, staring at the sky and soaking it all in.
It is truly one of nature’s best gifts. But have you ever wondered, what causes it? Who was the first person or people who saw the northern lights? Keep reading to explore some of the questions and you might as well learn something new!
THE FASCINATION, MYTHS AND LEGENDS!
Odin was the god and ruler of Asgard. The Vikings believed that every time there was a battle on Earth, Odin would pick his group of warriors- the Valkyries who wore armors and shields. Legends say that people believed the Northern Lights were illuminating the reflections of the armors of the Valkyries as they went for war.
For the Sámi, the indigenous Finno-Ugric people, the lights didn’t tell stories of heroism and bravery; instead, they were to be feared and respected in equal measure. The appearance of the Northern Lights was a bad omen.
In Finland, the name for the Northern Lights is revontulet, literally translated as ‘fire fox’. The name comes from the rather beautiful myth that Arctic foxes produced the Aurora. These fire foxes would run through the sky so fast that when their large, furry tails brushed against the mountains, they created sparks that lit up the sky.
WHO WAS THE FIRST ONE TO SEE THE NORTHERN LIGHTS?
For thousands of years, people have marveled at the Aurora Borealis, but it wasn't until the early twentieth century that science was able to provide an explanation for what was really happening. The first person to accurately explain the Aurora Borealis was a Norweigan scientist named Kristian Birkeland.
WHAT ARE THE NORTHERN LIGHTS? WHERE CAN WE FIND THEM?
The Northern Lights, one of several astronomical phenomena called polar lights, are shafts or curtains of colored light visible on occasion in the night sky.
These polar lights can be seen in both the northern and southern hemispheres. Northern lights are also scientifically called the ‘aurora borealis’ and southern lights are called ‘aurora australis’
The Northern Lights, as the name suggests, are especially related to the polar regions. They occur most frequently in a belt of radius 2500 km centered on the magnetic north pole. This so-called auroral zone extends over northern Scandinavia, Island, the southern tip of Greenland and continuing over northern Canada, Alaska and along the northern coast of Siberia.
WHEN CAN WE SEE THE NORTHERN LIGHTS?
One would imagine the Northern lights to occur in the wintertime, but in reality they are present the year round. Its just that it wont be seen when the nights are light as the background sky has to be fairly dark.
Northern Lights are often referred to as 'night aurora' because they occur on the night side of the Earth and they commonly appear in the early evening and continue late into the night. Although this is the most usual form of aurora, during winter on Spitzbergen, where it is dark even at midday, it is possible to observe the rarer 'day aurora' which occurs on the 'day side' of the Earth. The aurora lies well above the highest clouds, so we need clear skies to be able to see it. In fact, cloudy skies are the greatest obstacle for auroral observations in northern Norway and for this reason the inland regions are better suited than near the coast. The days around full moon are not conducive to viewing the Northern Lights because the background sky becomes so light. Finally, one should avoid cities and areas with much street lighting in order to experience the Northern Lights to the full.
HOW HIGH UP ARE THE NORTHERN LIGHTS?
Most aurorae occur between 90 and 130 km above sea level, but some, particularly the ray-like forms, extend to several hundred kilometers up. In comparison, the usual altitude for a jet aircraft is around 10km and the ozone layer lies between 20 and 30km so we have to be almost up at the heights of satellites orbits to be at the same height as the aurora. A consequence of its great height is that the aurora is visible at horizontal distances of several hundred kilometers.
WHAT CAUSES THE NORTHERN LIGHTS?
What happens in an aurora is similar to what happens in the neon lights we see on many business signs. Electricity is used to excite the atoms in the neon gas within the glass tubes of a neon sign. That’s why these signs give off their brilliant colors. The aurora works on the same principle – but at a far more vast scale.
The aurora often appears as curtains of lights, but they can also be arcs or spirals, often following lines of force in Earth’s magnetic field. Most are green in color but sometimes you’ll see a hint of pink, and strong displays might also have red, violet and white colors.
The colors in the aurora were also a source of mystery throughout human history. But science says that different gases in Earth’s atmosphere give off different colors when they are excited. Oxygen gives off the green color of the aurora, for example. Nitrogen causes blue or red colors.
The unique colors of the Northern Lights are created by the Earth’s spectra of gases and the height in the atmosphere where the collision of particles from the sun and the Earth’s gases takes place. Our naked eye can most easily see the green-yellow part of the spectrum where the sun emits most of its light. Green is the most common color observed but the Northern Lights can also appear white-gray. And a cloudy night if you’ve never seen them before, you might not even be entirely sure of what you’re looking at.
The Northern Lights can be faint enough not to be seen to the naked eye
Sometimes the Northern Lights are even present but not visible to the naked eye. We took a photo of some Icelandic horses nearby our cabin after we thought the Northern Lights had disappeared. We can't see them, but a camera still could.
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