The aurora borealis (northern lights), which occurs due to collisions between electrically charged particles from the sun and particles in the Earth's atmosphere, is seen over the sky in Finland. (Photo/Agencies)

The aurora borealis (northern lights), which occurs due to collisions between electrically charged particles from the sun and particles in the Earth's atmosphere, is seen over the sky in Finland. (Photo/Agencies)

The aurora borealis (northern lights), which occurs due to collisions between electrically charged particles from the sun and particles in the Earth's atmosphere, is seen over the sky in Finland. (Photo/Agencies)