It's planet Earth seen from the International Space Station through the shimmering glow of aurorae. Aurorae have the signature colors of excited molecules and atoms at the low densities found at extreme altitudes. Emission from atomic oxygen dominates this view. The eerie glow is green at lower altitudes, but a rarer reddish band extends above the space station's horizon. Also visible from the planet's surface, this auroral display began during a geomagnetic storm.
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From @lestrange