The Northern Lights could vanish from Scotland's skies by the 2050s, according to scientists.

Solar activity which causes the aurora is expected to drop a third by the middle of the century, experts from Reading University say.

As a result the display will become less common away from the North and South Poles, they claim, and Earth will be more vulnerable to cosmic radiation.

Dr Matthew Owens, who led the study, said: "The magnetic activity of the sun ebbs and flows in predictable cycles but there is also evidence that it is due to plummet, possibly by the largest amount for 300 years.

"If so, the Northern Lights phenomenon would become a natural show exclusive to the polar regions, due to a lack of solar wind forces that often make it visible at lower latitudes.

"As the sun becomes less active, sunspots and coronal ejections will become less frequent.

"However, if a mass ejection did hit the Earth, it could be even more damaging to the electronic devices on which society is now so dependent."

Auroras are created when solar winds made of electrically-charged particles ejected from the sun strike atoms in the atmosphere.

A drop in these solar winds would reduce the frequency and strength of auroras and cause the Earth's heliosphere - which shields the planet from cosmic radiation - to shrink.

Study co-author professor Mike Lockwood said: "If the decline in sunspots continues at this rate, and data from the past suggests that it will, we could see these changes occurring as early as the next few decades."

The study, Global Solar Wind Variations Over the Last Four Centuries, has been published in the academic journal Scientific Reports.