Why are we Seeing Northern Lights?

Is Earth the only Place where Aurora Borealis can take place?

Earth has recently experienced quite a lot of interesting events. Northern lights is right up there in the list as it raised many questions straightway after its first sight. They are also known as Aurora Borealis. The first question to answer here is, what it actually is? It is a natural light display in the Earth’s sky which is seen BEST around the poles of both the hemispheres. That’s the reason behind the name ‘polar lights’. The colors in which they have appeared till now includes red, green, yellow, blue and violet. The most common ones are pale green and pink. The pattern of their appearance is not consistent. It has varied from place to place and time to time.  They appeared in patches, arcs, rippling curtains or shooting rays that lightened the sky with a creepy glow.

They are produced when charged particles of Sun’s atmosphere collide with the gaseous particles of our planet. The gaseous particles of Earth are responsible for the color we see. The source of the most common color, pale green, is 60 miles high oxygen. Red auroras are also produced by oxygen but altitudes vary as it is about 200 miles high in the atmosphere. Nitrogen accounts for the blue or purple shade of auroras. The best areas to experience this are Northwest Territories, Alaska, Greenland, Iceland, Yukon, Nunavut, Siberia and Norway. Places where levels of pollution are not so high have better visibility for these auroras.

The basic reason that has come forward following an in-depth research is that solar wind brings particles from Sun towards Earth. As we know that Sun has very high temperature and non-stop massive explosions are taking place, the presence of free particles like electrons and protons is pretty understandable. The solar wind that flows from Sun towards Earth carries these charged particles. When that wind reaches the atmosphere of Earth, these particles collide with the molecules of different gases that are part of our environment. That is when we see these amazing colors in the sky. According to scientists, all this does not happen randomly and it follows a specific plan.

Researchers say that the solar storms that cause these auroras occur once every 11 years. They are also called ‘Sunspots’. That is the best time to experience these lights as the intensity is at its maximum during that storm. There have been 22 full cycles since the time, the storing of data of Sun was started. The latest peak came in 2013 but it was the weakest maximum in the last century. The Senior Science Advisor of NASA for Innovative Advanced Concepts program said:

“This solar cycle continues to rank among the weakest on record.”

These lights were seen before the advancement of technology took place and this gave way to a lot of superstitions and speculations. The history of these lights is proved by the old paintings that represent these auroras. Some of those pieces of art goes back to 30000 years. Many famous philosophers and authors mentioned them in their work including Aristotle and Descartes. The name aurora was given to these lights by Galileo Galilei in 1616.

He used the Roman myth according to which the goddess of dawn was called ‘Aurora’. Another interesting claim that came forward was that there were people who reported to have heard noises alongside these lights. This phenomenon has not been able to come into documentation yet. It is such a popular event in the Northwestern parts of America and Canada that ‘Yellowknife’ is the capital of Aurora tourism which is located in Northwest Territories, Canada.

A question arises here that as Sun is the center of our solar system, can we see northern lights on other planets as well? No scientific proof has been provided till now to accept or reject this claim but if we consider that other planets have some gases in their atmosphere, they must display these lights. The reason for this seems quite logical as the wind from Sun flows towards all the planets. But as these lights are seen only towards the poles of the Earth, presence of magnetic field is necessary. Considering the information we have right now, Aurora Borealis must occur at all other planets which have magnetic field and this includes Jupiter, Saturn, Uranus and Neptune.