BSL Astronomy Glossary - northern lights - definition
Definition: The Northern Lights, also known as the Aurora Borealis, are visible in the sky from the northern hemisphere. They look like a curtain of coloured light, glowing with pinks and greens. They are created when a solar explosion on the Sun releases particles into space. When some of these particles interact with the Earth’s magnetic field, the particles become excited and reflect different colours of light. The Earth’s magnetic field, created by the north and south poles, surrounds the planet. A similar phenomenon to the Northern Lights exists in the southern hemisphere, known as the Southern Lights or Aurora Australis. Both of these phenomena are usually only visible from the northernmost and southernmost areas of Earth and they are not visible from the areas around the equator.