Science
How do the northern lights work?
The northern lights (the aurora) happen when charged particles from the Sun crash into gases high in Earth's atmosphere, making them glow. Earth's magnetic field funnels these particles toward the poles, which is why the lights appear there.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how the northern lights works.
Step by step
- 1The Sun constantly streams out charged particles called the solar wind.
- 2Earth's magnetic field steers many of these particles toward the north and south poles.
- 3High in the atmosphere, the particles collide with oxygen and nitrogen gas.
- 4Those collisions energize the gas, which releases the energy as colored light.
- 5Oxygen tends to glow green or red; nitrogen gives blues and purples.
Frequently asked questions
- Why are the northern lights usually green?
- Green comes from oxygen atoms about 100 km up being energized by incoming particles — the most common and visible auroral color.
- Why do they only appear near the poles?
- Earth's magnetic field channels the Sun's charged particles toward the magnetic poles, so the glow concentrates in the far north — and far south.
- Are the southern lights the same thing?
- Yes — the aurora australis is the southern version, caused by the same process around the South Pole.