Colourful clouds above Norway

Ben Domensino, 9 April 2019

Strange and colourful clouds appeared in the sky above Norway last week as scientists take one step closer to understanding the mysteries of Earth's upper-atmosphere.

Most of the weather we can see and experience happens in the lowest 10km of Earth's atmosphere. But our planet's atmosphere actually extends more than 1,000km above the ground, and there's still a lot we don't know about what goes on at higher altitudes.

While scientists collect millions of weather observations near the surface every day, it's much harder to physically observe what goes on a few hundred kilometres above the ground.

NASA scientists overcame this problem by creating a mysterious display of colourful clouds in the sky above Norway last Friday.

Image: Colourful clouds appear above Norway on April 5th. Credit: NASA

Two sounding rockets released small amounts of gases, called vapour tracers, into the atmosphere between 115 and 240km above the Norwegian Sea. These tracers, which are similar to those used in fireworks, resulted in a unique display of colourful clouds that could be seen from the ground.

This visually striking experiment allowed scientists to observe the behaviour of upper-level winds and the movement of particles in this unfamiliar part of our atmosphere.

According to NASA, the gases used to create the artificial clouds are not harmful to people or life on the ground. In fact, the rockets release less material than a typical fireworks display.

This experiment was part of NASA's Auroral Zone Upwelling Rocket Experiment (AZURE) mission, which is part of an international collaboration to study the processes occurring inside a region of our atmosphere called the polar cusp.

You can find out more about NASA's AZURE mission here: