Alexandra Pope, staff writer
September 10, 2011 — The aurora borealis -- northern lights -- were visible across much of Canada and the northern United States Friday night.
The impressive light show came courtesy of a coronal mass ejection (CME) -- a massive burst of solar wind that struck the Earth's magnetic field, generating a strong geomagnetic storm.
The result was brighter, more dramatic auroras in areas that typically see auroras. The Northern Lights were also spotted as far south as Washington and Michigan and as far east as Maine.
Astronomers say more dramatic aurora borealis could be visible over the next few days as one or two more CMEs approach the Earth.
The Space Weather Prediction Centre of the U.S. National Oceanic and Atmospheric Administration offers tips for spotting aurora borealis.
The weather plays a big role in the visibility of auroras; find out what's in store for your area after dark.