Space Encyclopedia
🌌 Aurora
Overview
The aurora is the visible signature of space weather. Charged particles from the Sun, funneled by Earth's magnetic field, slam into oxygen and nitrogen atoms in the upper atmosphere and make them glow — green from oxygen at 100–300 km, red at higher altitudes, blue and purple from nitrogen.
Key facts
- •Northern lights: aurora borealis
- •Southern lights: aurora australis
- •Typical altitude: 100–300 km
- •Main colors: green (oxygen), red (high oxygen), blue/purple (nitrogen)
- •Best viewing: high latitudes, dark skies, Kp 5+
Why it matters
The aurora is the most beautiful — and most watched — form of space weather. Our live aurora forecast, Kp tracker, and IMF Bz monitor exist because millions of people want to know, tonight, whether they'll see the northern lights.
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Frequently asked questions
What causes the aurora?
Charged particles from the solar wind get trapped by Earth's magnetic field and funneled toward the poles. When they collide with atmospheric gases, those gases glow — green from oxygen, red at higher altitudes, blue/purple from nitrogen.
Can I see the aurora tonight?
Check our live aurora forecast. Visibility depends on the Kp index, cloud cover, darkness, and your latitude. At Kp 5+, the aurora often becomes visible from mid-latitude locations.
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