what causes the northern lights?

The northern lights are caused when charged particles from the Sun hit Earth’s upper atmosphere and interact with our planet’s magnetic field, making atmospheric gases glow.

What the northern lights are

• The northern lights (aurora borealis) are shimmering patterns of colored light that appear high above Earth’s surface, usually near the polar regions.

• They form as “curtains,” arcs, and rays of light typically 80–300 kilometers above the ground, far higher than airplanes or weather clouds.

How the Sun creates them

• The Sun constantly throws out a stream of charged particles (mainly electrons and protons) called the solar wind, and sometimes more intense bursts during solar storms, flares, and coronal mass ejections.

• When these faster, denser clouds of particles reach Earth, some are guided by our magnetic field toward the polar regions, forming oval-shaped “auroral zones” around the magnetic poles.

What happens in Earth’s atmosphere

• As the particles rush down magnetic field lines, they collide with atoms and molecules of gases such as oxygen and nitrogen in the upper atmosphere, transferring energy to them.

• When those excited atoms and molecules release that extra energy, they emit photons (light), and countless such emissions together create the glowing aurora visible from the ground.

Why the colors and shapes vary

• Different gases and altitudes produce different colors: green comes mainly from oxygen around 100 kilometers up, red from oxygen higher up, and purples and blues from nitrogen.

• The flowing, wavy forms trace Earth’s magnetic field lines; changes in the solar wind and magnetic field cause the lights to ripple, flicker, or suddenly brighten in dramatic bursts.

When and where they are strongest

• Auroras appear most often in high-latitude regions such as northern Scandinavia, Canada, and Alaska, where the auroral oval usually sits.

• During periods of heightened solar activity, strong solar storms can push the auroral oval farther from the poles, making the northern lights visible much farther south than usual.

Information gathered from public forums or data available on the internet and portrayed here.