Over the last week or so there have been some incredible displays of the Northern Lights, or Aurora Borealis. Not something that trips lightly off the tongue but, if you are fortunate enough to experience this wonderful sight, it is an experience that will stay with you for a long time.
Usually the Aurora Borealis are seen in northern latitudes – northern Scotland, Scandinavia and areas north of the Arctic circle. But just lately, as a result of severe space weather conditions, they have been seen in many parts of the UK. (You won’t see Northern Lights if you live in the southern hemisphere – BUT you may well see the Southern Lights, or Aurora Australis.)
The Lights appear as vast expanses of colour – green, pink, red, yellow, blue and violet. These patches shift and change, creating spectacular dance-like movements in the sky. They are best seen away from areas of light pollution and they can extend from 50 to 400 miles above the Earth’s surface. The lights occur due to solar activity as charged particles in the solar wind collide with molecules in the upper atmosphere. Solar winds are the result of charged particles streaming away from the sun at speeds of up to one million miles per hour and when the magnetic polarity of the solar wind is opposite the Earth’s magnetic field the two combine to allow the energy particles to flow into the Earth’s magnetic north and south poles.
The colours vary depending on what gases are given off during the collision. Oxygen gives green light lower down and red higher up; nitrogen causes blue and violet colours. But if all the science is making your brain spin don’t worry about it – just enjoy the amazing effects produced and be happy that you are able to experience it. It truly is one the world’s greatest wonders.
