In Pics: Stunning Aurora Substorm Captured By Stargazers
Many planets, including Earth, possess a magnetosphere—a massive magnetic shield generated by their molten metal core that extends deep into space. Earth's magnetosphere protects the planet by absorbing harmful charged particles from space.
When parts of the magnetosphere become overwhelmed with energy, a geomagnetic storm can occur, similar to thunderclouds forming before a storm. During such a storm, the stored energy channels down Earth's magnetic field lines and precipitates into the atmosphere like a heavy rain.
This influx of particles injects millions of amps into the atmosphere, creating spectacular auroral displays visible far from the poles.
Solar Activity and Coronal Mass Ejections
Occasionally, the Sun launches powerful eruptions called coronal mass ejections (CMEs). These explosive events propel massive amounts of solar material into space as enormous flying blobs.
Aurora Colors and Their Causes
- Green auroras, the most common, occur when energetic electrons excite oxygen at altitudes between 100 and 200 km.
- Blue auroras result from nitrogen excited at the same altitudes (100–200 km).
- Nitrogen below 100 km causes reddish-purple or pink glows.
"Aurora colors result from energetic particles colliding with gases in the upper atmosphere, with each gas producing distinct colors at different altitudes."
These beautiful lights brighten our skies and remind us of the dynamic interactions between Earth and space weather.
Author's summary: Earth's magnetosphere and solar eruptions interact to create vibrant auroras, with colors reflecting atmospheric gases excited by energetic particles.