The Northern Lights could be visible from the UK again on Monday night, after stargazers were treated to a stunning display on Sunday.
Also known as Aurora Borealis, the Northern Lights are a fairly rare occurrence in the UK, and when they can be seen, it is often only in the most northerly parts of the country.
But on Sunday they were visible as far south as Cornwall, and forecasters are expecting a repeat performance tonight.
What are the Northern Lights?
The Northern Lights occur as a consequence of solar activity and result from collisions of charged particles in the solar wind colliding with molecules in the Earth’s upper atmosphere.
The Met Office explains: “Solar winds are charged particles that stream away from the Sun at speeds of around 1 million miles per hour. When the magnetic polarity of the solar wind is opposite to the Earth’s magnetic field, the two magnetic fields combine allowing these energetic particles to flow into the Earth’s magnetic north and south poles. Auroras usually occur in a band called the annulus (a ring about 1,865 miles across) centred on the magnetic pole. The arrival of a Coronal Mass Ejections (CME) from the Sun can cause the annulus to expand, bringing the aurora to lower latitudes. It is under these circumstances that the lights can be seen in the UK.”
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 the Earth, while at 100-200 miles, rare, all-red auroras are produced. Nitrogen causes the sky to glow blue, and has a purple hue when higher in the atmosphere.
How can I see the Northern Lights tonight?
The best conditions to view the lights are when the sky is dark and clear of any clouds. This means the best time to see them is after the Sun sets, which is shortly after 5.30pm.
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 Aurora Watch UK Twitter account, run by space physicists at the University of Lancaster, tweets when the Northern Lights may be visible from the UK.
