The skies over northern Europe have been illuminated with an intense display of the northern lights after a week of massive solar storms showered the Earth with radiation. Video shot last weekend in Norway showed the eye-catching effect of the Aurora Borealis in the skies above Birtavarre. The lights are a familiar sight for Scandinavians, but even experienced stargazers were stunned by the intensity of the aurora borealis that swept across their night's sky on Tuesday, after the biggest solar storm in more than six years. An aurora appears when a magnetic solar wind slams into the Earth's magnetic field, exciting electrons of oxygen and nitrogen. Even before particles from the solar storm reached the Earth on Tuesday, a different aurora on Monday night was dancing across the sky as far south as Ireland and England, where people rarely get a chance to catch the stunning light show..