Do You Know?: Do You Know What is the Aurora?

The aurora is a beautiful atmospheric phenomenon appearing as bands of coloured light sometimes visible in the night sky in the polar regions of the earth. In the northern region, it is known as the aurora borealis or the Northern Lights. In the southern region, it is known as the aurora australis or the Southern Lights.

Auroras take on different appearances. They can look like an orange or red glow on the horizon - much like a sunrise or sunset. They may also look like curtains or ribbons and move and undulate during the night.

Auroras can be green, red or blue. Often they will be a combination of colors, with each color visible at a different altitude in the atmosphere.

Blue and violet: less than 120 kilometers (72 miles)
Green: 120 to 180 km (72 to 108 miles)
Red: more than 180 km (108 miles)

Aurora over Bear Lake, Alaska

Red aurora above Pioneer Peak, Alaska

How do auroras happen? The solar wind from the Sun can bring fast-moving particles towards the Earth. Some of them are then guided by the Earth's magnetic field towards the north and south magnetic poles. As they approach the Earth, the particles interact with the atmosphere making it glow in many different colours and causing the effect we call an aurora.

Illustration of how the aurora is formed

Auroras are like neon lights. Neon lights work by exciting gases inside of a tube with electricity. The resulting colors that you see are a result of the different gases used to make neon lights. In an aurora, the neon colors you see are the different wavelengths of light from gases high in the atmosphere.