Valentine’s Surprise

Valentine’s Surprise

For Valentine's Day, night-sky photographer Alan Dyer received not red roses, but red auroras. "It was an odd display. Instead of the usual green, the lights over Manitoba, Canada, on Feb. 14th were a beautiful shade of red," says Dyer, who took this 25 second exposure using a Canon 6D digital camera and a fish-eye lens:

"The bright light at the right is Jupiter," he points out. "Later, the aurora took on the more normal appearance with green curtains topped by fringes of red."
Red auroras are not fully understood. They occur some 300 to 500 km above Earth's surface, much higher than ordinary green auroras. Some researchers believe the red lights are linked to low energy electrons from the sun, which move too slowly to penetrate deeply into the atmosphere. When such electrons recombine with oxygen ions in the upper atmosphere, red photons are emitted. At present, space weather forecasters cannot predict when this will occur.
Later today, a solar wind stream is expected to hit Earth's magnetic field, prompting NOAA forecasters to estimate a 40% chance of polar geomagnetic storms on Feb. 15th. Auroras are likely, although no one can say if any of them will be red.

From SpaceWeather.com