NASA - National Aeronautics and Space Administration

Colliding Auroras Produce an Explosion of Light

A fast-moving knot of auroras is poised to collide with a slower moving curtain hanging over the Arctic. THEMIS all-sky imagers (ASIs) photographed the collision on Feb. 29, 2008. Credit: Toshi Nishimura/UCLA
› Larger Image A network of cameras deployed around the Arctic in support of NASA's THEMIS mission has made a startling discovery about the Northern Lights. Sometimes, vast curtains of aurora borealis collide, producing spectacular outbursts of light. Movies of the phenomenon were unveiled at the Fall Meeting of the American Geophysical Union today in San Francisco.

"Our jaws dropped when we saw the movies for the first time," said space scientist Larry Lyons of the University of California-Los Angeles (UCLA), a member of the team that made the discovery. "These outbursts are telling us something very fundamental about the nature of auroras."

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The Mission

THEMIS is a mission to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection.

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