What causes the Northern Lights?
The lights in the sky have occurred since the dawn of our planet. Dinosaurs walked under them, just as we do today. They are a constant of our world – always there, even when it’s too bright for us to see them. But what are they and how are they created?
Why can we see different colours?
The Earth’s atmosphere is made up of different atoms, like oxygen and nitrogen, and it’s these atoms that cause the colours we can see in the Northern Lights. These atoms become excited at different levels in the atmosphere.
The most common colour seen in the Northern Lights is green. When the solar wind hits millions of oxygen atoms in the Earth’s atmosphere at the same time, it excites the oxygen atoms for a time and then they decay back to their original state, when they emit the green hue we can see from the ground.
The red light we sometimes see is also caused by oxygen atoms. These particles are higher up in the atmosphere and are subject to a lower energy red light emission. The red colour is always there, but our eyes are five times less sensitive to red light than green, so we can’t always see it.
A large part of the Earth’s atmosphere is made up of nitrogen. The particles from the solar wind must hit nitrogen atoms a lot harder in order to excite them. Once the nitrogen atoms begin to decay, they emit a purple coloured light. This is quite a rare colour to see, and usually only happens during a particularly active display.
For the best chance of seeing the lights, you need to be under or close to one of the auroral ovals. As we sail towards the Arctic Circle, your chance of seeing the Northern Lights improves, but there are a lot of factors to consider when hunting the lights. Read our Northern Lights FAQ and learn how you can increase your chances of catching a glimpse of this awe-inspiring light show in the sky.
See the Northern Lights with Hurtigruten
Get unique insight and knowledge about the Arctic sky and the greatest lightshow on Earth, the Aurora Borealis, on the popular Astronomy Voyage along the mesmerising Norwegian Coast.
This limited voyage is accompanied by special lecturers - experts on astronomy and expeditions to see the Northern Lights.
- Duration: 12 days
- Route: Bergen - Kirkenes - Bergen
- Sailing period: January 2019 - December 2020