What does that mean? Well, the Northern Lights are caused by solar flares -- when the sun releases great streams of plasma and electrons into space. As the stream of electrons hits the Earth, it interacts with our atmosphere and produces light. Many, but not all, solar flares are released from sunspots. The sunspots appear in 11 year cycles. It takes about 4 years for the sunspots to reach a maximum, and 7 to go back to minimum. The most recent minimum began in 2008, and lasted for about 2 years, which is longer than normal. (And that's your space weather lesson for today).
So, when we left, the sun was still at its minimum, but now it's heading back towards maximum again. The Aurora has come out a couple times this fall, but it's been cloudy, or the moon has been out. Friday was clear, and the display was active enough to see it from midtown, even with all the light pollution.
What is it like to see the Aurora? Imagine you have two different colors of water that are mixing together. They don't just instantly become mixed, one color will flow and stream into the other.
That's what watching the Aurora is like. It's a river of light in the sky.
|Not just green; faint purple and red showed up as well.|
Sometimes, it comes down straight over you, looking like a "rain" of light.
|A whirlpool in the river|
Other times, it goes off and does its own thing. It's constantly moving and changing, sometimes flashing on and off, sometimes marching down from above like other worldly beings.