The Northern Lights are heading south

LOOKING for the bright lights? Then stay away from the big city tonight.

• The Northern Lights are an impressive sight, and the chances of seeing them in Scotland have increased as a result of two solar storms. Picture: PA

Astronomers are predicting the sun may be about to put on a brilliant colourful light show which should be visible from parts of Scotland.

Two minor solar storms that flared on Sunday are shooting tons of plasma directly at Earth. When it arrives, it could create some spectacular Northern Lights, or aurorae, in the early hours today and again about midnight tonight.

"This eruption is directed right at us and is expected to get here early in the day on 4 August," said astronomer Leon Golub, of the Harvard-Smithsonian Center for Astrophysics (CfA). "It's the first major Earth-directed eruption in quite some time."

The eruption, called a coronal mass ejection, was caught on camera by NASA's Solar Dynamics Observatory (SDO) - a spacecraft that launched in February.

"We got a beautiful view of this eruption," said Mr Golub. "And there might be more beautiful views to come, if it triggers aurorae."

According to the experts, when a coronal mass ejection reaches Earth, it interacts with our planet's magnetic field, potentially creating a geomagnetic storm.

Mr Golub added: "Solar particles stream down the field lines toward Earth's poles. Those particles collide with atoms of nitrogen and oxygen in the atmosphere, which then glow like miniature neon signs."

Usually only regions closer to the Arctic Circle can see the aurora, but solar storms pull them south.

US scientists said residents of northern regions, from Maine to Michigan and anywhere farther north around the globe - might see unusual Northern Lights.

The Sun goes through a regular activity cycle about 11 years long on average. The last solar maximum occurred in 2001. Its latest minimum was particularly weak and long-lasting.

Astronomers say this eruption is one of the first signs that the sun is "waking up" and heading toward another maximum.

A spokeswoman for the Harvard-Smithsonian Center for Astrophysics, said: "Unlike hurricane forecasts, where the ground track can be predicted with some accuracy, there is no science to predict specific locations of aurora visibility."

However, she said there was a "very good chance" of seeing the spectacular event in Scotland: "Best views are from a dark sky location well away from city lights."

Mike Alexander, from the Galloway Astronomy Centre, said it would take about 48 hours from the time of the storm for the light show to reach Earth.

"It's heading our way, and it's possible we will see something on 4 August. But I've a nasty feeling it will occur in daylight."

He said the possibility of seeing it increase the further north you were, with people living in the Borders and into England having minimal chance.

"This is not a major explosion on the Sun, there are much bigger ones - hundreds of times bigger - which can cause aurorae that can be seen into northern Europe.

"This one is going to be one of the top end of Scotland. Certainly, people have got clearer skies in the north."

He said: "It's like someone has a searchlight following the horizon and switching it on and off, shining a light on the sky."

The chances of seeing the phenomenon also rests on whether it will be dark enough at this time of year - and the weather.

Last night it was mostly cloudy across the Highlands, and today rain is expected over the North-west and islands, although clearer and brighter spells are expected around Inverness

Professor Mike Kosch, chair in experimental space science at Lancaster University's physics department, said: "To see aurora over Scotland would normally require a fairly major geomagnetic disturbance.

"Although there may be a chance of seeing the aurora over the north of Scotland, the sky may be not dark enough at this time of the year to actually see it properly.|

He added: "The chances of an aurora occurring over Scandinavia is much greater, but the midnight sun will prevent any viewing of it."

Higher is better to see nature's spectacular show

THE lights are known as the aurora borealis (northern lights) in the northern hemisphere, and the aurora australis in the southern hemisphere.

In general, you are more likely to see an aurora if you are at a high latitude, closer to the north (or south) pole.

The US Space Weather Prediction Centre in Boulder, Colorado, says that as the earth's magnetic poles are not exactly in line with the geographic poles, the latitude of interest is the magnetic latitude.

The magnetic latitude of Reykjavik and northern Norway, where aurorae are common, is 64 degrees, Anchorage in Alaska is 60, while Edinburgh is 53 and London 47.

While it is possible to see aurora activity anywhere in the UK when conditions are right, it is more common the further north you go. The best place to see the aurora borealis in Britain is therefore in Shetland. Experts advise that the best locations are away from large towns and cities, facing north and in a spot with clear dark skies and minimal light pollution.

When geomagnetic activity is low, the aurora typically is located, in the hours around midnight, at about 67 degrees magnetic latitude. When geomagnetic activity is very high, the aurora may be seen at mid and low latitude locations.