Weather

Get photographer Mark Humpage onto the subject of the Northern Lights, sometimes known as the Aurora Borealis, as he waxes lyrical.

It was, he said, "A beautiful, wonderful experience."

He recently returned from spending a week in the Arctic circle and has brought back with him a sheaf of magnificent photographs.

Take a look at Mark's amazing pictures, read his diary and listen to his interview with BBC Leicester's Tony Wadsworth about the experience...

Getting them was no easy matter. "We had to travel 500 metres from the main town of Tromso to actually get clear skies," he says. Tromso is Norway's northernmost city and is situated 300km inside the Arctic circle.

"When we did get clear skies it was 20 below, winds howling and camera gear getting covered in ice and snow for five and six hours at a time."

Magical

"But when we saw the lights, my word it was a magical experience!

"There's a famous saying with regard to the Northern Lights. No pencil can draw it, no colours can paint it and no words can describe it. That is the truth!

"There were ribbons of colour - greens, reds, pinks and oranges just flowing and weaving through the skies...

"It's impossible to describe it and I just hope the photographs we brought back can do some kind of justice to it because if there are any magical experiences in the world that's one of them."

Plasma

But what causes the Aurora? The answer to that is quite complicated but it is all to do with solar activity.

The sun gives off high-energy charged particles that travel out into space at speeds of 300 to 1200 kilometres per second. A cloud of such particles is called a plasma.

The stream of plasma coming from the sun is known as the solar wind. As the solar wind interacts with the edge of the earth's magnetic field (magnetic north or south), some of the particles are trapped by it and they follow the lines of magnetic force down into the ionosphere.

Spectacle

When the particles collide with the gases in the ionosphere they start to glow, producing the spectacle that we know as the Auroras.

As this explanation suggests, the Northern Lights have their southern counterpart.

Mark's photographs are remarkable. "I used a wide-angle lens to maximise the area of the sky I could photograph... The lens also enhances the image."

The spectacle has caused feelings of awe since time immemorial. Marks says that the ancient Vikings described it as the "contrails [vapour trails] of Thor's chariot being pulled by three goats".

This struck a chord with Mark. "When you see it you can imagine a heard of animals racing across the sky leaving tracks behind."