How Auroras (Northern and Southern Lights) Form

Tap an item to see the details.

Solar Wind Meets Earth's Magnetic Field

The aurora begins when solar wind — a stream of charged particles released by the sun — gets captured by Earth's magnetic field and funneled down toward the polar regions.

Why Colliding Particles Glow

When the funneled solar wind particles collide with oxygen and nitrogen atoms and molecules high in the atmosphere, the atmospheric particles absorb energy, become excited, and then release light as they return to their normal state — that light is the aurora.

Why Color Changes With Altitude

Collisions with oxygen atoms at roughly 100-300 km altitude produce green light, while higher altitudes tend to produce red; collisions with nitrogen molecules can produce blue or purple light.

Where to See the Aurora

Auroras are best observed at high latitudes near the Earth's magnetic poles — Norway, Iceland, northern Canada, Alaska, and Finland are among the classic viewing locations.

Stronger Solar Activity Means More Active Auroras

During periods of high sunspot activity, the solar wind intensifies, and auroras are sometimes observed at lower latitudes than usual.

The Southern Hemisphere Has Auroras Too

Just as the Northern Hemisphere's aurora is called Aurora Borealis, the aurora observed around Antarctica is called Aurora Australis (the "southern lights") — it forms through the exact same process.

A Light Show Made by the Sun and Earth Together

The aurora that lights up the night sky looks like a mysterious natural wonder, but it's actually a physical phenomenon created by particles from the sun interacting with Earth's magnetic field and atmosphere. Understanding the mechanism also explains why it's best seen near the poles.

Comets and Asteroids Are Worth a Look Too

If phenomena that originate in space fascinate you like the aurora does, comets and asteroids are another great topic to explore.

Frequently Asked Questions

Can the aurora be seen from mid-latitude or low-latitude countries?

Countries at mid or low latitudes rarely see the aurora because of their position, but during periods of extremely strong solar activity, a faint aurora has occasionally been reported in some unusually low-latitude locations.

When is the aurora easiest to see?

The chances are best from late autumn to early spring, when nights are long and skies are clear, especially around midnight.