Most of us know what the Northern Lights look like -- but not all of us know how they're created.
“Some people think that (the Northern Lights are) some kind of light that reflects off the polar ice caps. This is not true. Northern Lights are actually related to activity on the sun,“ says astronomer Andrew Yee.
The sun frequently generates energy as visible light, but it also releases energy in other forms of radiation -- like x-ray or energetically-charged particles.
“These particles carry energy away from the sun, and when they slam into the Earth's atmosphere, they collide with the atoms in the upper atmosphere and deposit energy to those atoms,“ says Yee. “But that's not where the atoms prefer to stay. They prefer to go to the lowest energy state, and so eventually they release the excess amount of energy in a form of light -- so we see that as Northern Lights.
While we often see the lights dance across the sky in shades of red, green or blue, sometimes they're just white. “That's because the colour level is so low that our eyes can not detect the colours,“ Yee says. “But if you take a picture with a camera, you will see all these different colours then.“
Right now, the sun is heading towards a more active phase of the solar cycle. This means stargazers can prepare to see more auroras in the near future.