Sky-gazers in parts of the UK may be treated to a display of the northern lights on Thursday night as solar winds race towards Earth at about one million miles per hour. People in Scotland, northern England and Northern Ireland may have the best chance to view the colourful aurora which is caused by charged particles from the sun colliding with molecules in the Earth’s upper atmosphere.
The charged particles are a result of a phenomenon known as coronal mass ejection – which is sudden release of plasma from the sun’s corona, the outermost part of its atmosphere. The Met Office has said the northern lights will be visible at night from July 6 to July 8, clear skies permitting.
A spokesman said: “The northern lights may be enhanced overnight tonight with the arrival of a coronal mass ejection. They’re most likely to reach Scotland, parts of northern England and Northern Ireland. However, visibility may be poor for many, with cloud and rain for many in those regions overnight, as well as only a short window where it’s dark enough as we’re in summer.”
Don Pollacco, a professor at the University of Warwick’s Department of Physics, said that the northern lights – also known as the aurora borealis – are caused by the interaction of particles coming from the sun with the Earth’s atmosphere which are channelled to the polar regions by the planet’s magnetic field.
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. For example, he said, oxygen produces green light while nitrogen causes the sky to glow red.
Prof Pollacco added: “These shapes change quickly over timescales of minutes or even seconds. To predict exactly where you can see the northern lights is difficult as conditions can change quickly.
“The current storm is said to be visible from northern England but they are notoriously difficult to predict. However, one thing is for sure, and that is that you are unlikely to see them from a brightly lit city environment – you need to go somewhere dark and look towards the northern horizon. So, you would preferably be in the countryside away from street lights.”
