Imagine standing underneath a pitch black sky, when suddenly it erupts with color. How could this be? The Alaskan Inuits believed that the lights reflected the spirits of their hunted animals. Other cultures had their own explanations for the amazing Aurora Lights. The scientific explanation for this awe inspiring phenomenon is found in how they are formed.
What makes them the colors they are
What colors do they produce? When the gas particles collide with low-altitude oxygen molecules, they produce the most common light yellowish green color. When they hit high-altitude oxygen molecules, they make an uncommon all-red color. And when they come in contact with the nitrogen molecules, high or low, they make the sky light up in blue or purplish red. The lights can appear 50-400 miles above the earth’s surface.
The part the Earth’s magnetic field plays in the lights
The earth’s magnetic field protects the planet we call home. Without it, the ozone layer of Earth, which protects it from harmful radiation, would be stripped away by the charged particles that come from the sun. A lot of the gases are repelled by the magnetic field. So how do they break through to produce the famous Aurora lights? At the two poles, the field is weaker than the rest of it, so when the gases hit the field, some of them escape through to the poles, which is why they only appear around there.
Why they are called the Northern and Southern lights
The lights are called the Northern and Southern lights because of where they appear. Since the gas particles only enter at the poles, that is the only place they can appear. In Greek, Boreas was the name of the god of the north wind and the lights that appear in the North pole are called the Aurora Borealis. In Latin, auster means south wind, which is why when they appear in the South pole, they are called the Aurora Australis.
How the lights formed
The lights are formed when gas particles coming from the sun collide with oxygen and nitrogen particles causing them to light up in color. The lights start as gases from the sun (“solar wind”) traveling through space until they hit the molecules in the Earth’s atmosphere, producing different colors.
What colors do they produce?
When the gas particles collide with low-altitude oxygen molecules, they produce the most common light yellowish green color. When they hit high-altitude oxygen molecules, they make an uncommon all-red color. And when they come in contact with the nitrogen molecules, high or low, they make the sky light up in blue or purplish red. The lights can appear 50-400 miles above the earth’s surface.
What time of the year the lights appear
The lights peak around every 11 years. However, they are active all year round. In the north, winter is the best season to witness them. From April to August, the lights are not visible because it is daylight 24 hours a day. Northwestern parts of Canada are the best places in North America to see the Northern lights. The Southern Indian Ocean and Antarctica are the best places to see the Southern lights.
In the future, the aurora lights may become limited in places outside of the poles. So go witness this spectacular show of lights for yourself before they fade away!