Aurora

The Aurora Borealis (or Northern Lights) is a spectacular natural phenomenon which can occasionally be seen in the night sky over Britain.

Aurora is sparked by sunspots - dark, intensely strong, Earth-sized magnetic fields on the sun's surface. The sunspots are the trigger for the mass ejections of the solar particles. When the particles hit oxygen and nitrogen atoms in the upper atmosphere, they strip the atoms of their electrons and leave them in an excited state, causing them to glow.

The Earth's magnetic field then draws the particles towards the poles. North is normally the direction to look, but when the geomagnetic activity is high be aware that the aurora may be south of you.