When charged particles carried by solar winds slam into the planet, molecules of nitrogen and oxygen are excited in the atmosphere. The excited particles jump to different energy levels, releasing in the process colourful light in a wide variety of hues. In the Northern Hemisphere, the shimmering lights are popularly known as the Northern Lights. The Southern Lights, or the Aurora Australis, are the Southern Hemisphere’s counterpart.
What causes the Northern Lights to glow at night?
The incredible auroras, which can be seen from the UK, are the result of solar particles travelling 93 million miles to hit Earth.
According to the Met Office, particles carried by solar winds wash over our planet and interact with the air our atmosphere.
The Met Office said: “Depending on which gas molecules are hit and where they are in the atmosphere, different amounts of energy are released as different wavelengths of light.
“Oxygen gives off green light when it is hit 60 miles above Earth, whilst at 100 to 200 miles rare, all-red auroras are produced.”
Nitrogen molecules, on the other hand, glow with beautiful blue and purple light.
Can the Northern Lights be seen from Scotland?
The Northern Lights favour the northernmost parts of the world extending deep into the Arctic circle.
The farthest parts of Canada, Alaska, Russia and Scandinavia are best situated to see the Northern Lights.
But depending on the severity of solar winds washing over Earth, the Northern Lights can extend further down south.
When a powerful solar storm erupted in 1859, the so-called Carrington Event produced aurora as far down south as Cuba.
Here in the UK, the Northern Lights are best seen from Scotland, North England, North Wales and Northern Ireland.
Depending on the conditions, the Met Office said the auroras might even be seen throughout the country.
The Met Office said: “Ideally, the lights will be best viewed away from any light pollution, in remote areas, facing the northern horizon – north-facing coasts produce some of the best viewing locations.
“The northern lights are most active during the Equinox and Solstice in March/April and September/October.”
Services like AuroraWatch at Lancaster University, keep track of aurora activity over the UK.
On September 20, at 4pm BST (3pm UTC), AuroraWatch did not report any activity in the atmosphere.
If there is any geomagnetic activity in the atmosphere, the service will issue an alert.
A Yellow Status alert, for instance, suggests an aurora “may be visible by eye from Scotland and may be visible by camera from Scotland, northern England and Northern Ireland”.
However, visibility will still depend on the weather in your local area.