Photographer Brad Goldpaint captured this view of the northern lights over Crater Lake, Ore., early Sunday.
A double-burst of solar particles sparked auroral lights over the weekend, as expected — but at least in some parts of the world, the colors were not what you'd expect. Instead of the typical greenish glow, observers reported seeing reds, pinks, violets and even blues.
"It's been many years since I saw the blue in our auroras, but Saturday night they came back," John Welling reported in a note accompanying the photo he posted to SpaceWeather.com.
Pinks, reds and blues also dominated the scene captured on camera early Sunday by Brad Goldpaint, from a vantage point above Oregon's Crater Lake. In an email, Goldpaint told me the opportunity came about "by pure coincidence."
"Capturing this famous light show had been a dream of mine for several years, but I could not have imagined the lights showing up in my own backyard!" Goldpaint wrote. "After setting up near the Rim Village Visitor Center lookout area, I began to notice a faint band of moving light slowly making its way from behind the Watchman Tower, around 1:30 a.m. My camera began picking up bright pink bursts of light towards the north, with what also looked like unfamiliar vertical bands of light stretching upwards from the horizon. I quickly changed my camera’s white balance to confirm I was not picking up some random light pollution, or hallucinating in my drowsy state. Following additional exposures, I came up with the same amazing results. The magical shifting scene continued until sunrise, and like most days in the wilderness, I was awed and humbled by true nature personified."
The photo now graces Brad's portfolio at GoldpaintPhotography.com.
The colors of the aurora depend on the wavelength of the light emitted when fast-moving, electrically charged particles from the sun interact with different types of atoms and ions in Earth's upper atmosphere. If the particles hit mostly oxygen atoms, the light will be in the greenish-yellowish-reddish range. Collisions with nitrogen atoms produce the blue, purple and deep red hues.
The altitude of the auroral glow also affects the color: At altitudes between 60 and 120 miles (100 and 200 kilometers), the oxygen emissions tend toward the green side of the spectrum. At higher altitudes, you'll see more red. Blend all those colors, and you get a beautiful, wide-ranging palette.
The "Causes of Color" website provides a fuller spectrum of information. And speaking of a fuller spectrum, here are more of the weekend's colors, plus a bonus video:
Pink and purple rays highlight this picture of the aurora as seen from South Dakota's Black Hills by Randy Halverson. Technical details: Canon 5D Mark III, Canon 24-70, f/2.8 ISO 3200, 20-second exposure. For more of Halverson's images, click on over to Dakotalapse.com.
Stephen Voss snapped pictures of the southern lights from a spot near Invercargill in the south of New Zealand. "A dull arc hung around for a couple of hours before suddenly exploding with a mixture of rays and curtains," Voss told SpaceWeather.com. Check out Voss' gallery at Deep South Astrophotography.
Scott Lowther snapped this panoramic picture of Saturday night's auroral display as seen from Tremonton, Utah. The shot was taken with a Nikon D5000 and a 55mm lens at f/1.4 with 6-second exposures. For more of Lowther's photos, check out the Art by Earthlings website.
Shawn Malone / LakeSuperiorPhoto.com
Shawn Malone snapped this picture before dawn on Sunday morning from Marquette, Mich. "Got to witness the tail end of aurora activity as the skies cleared about 15-20 minutes before the sunrise light moved in," Malone told SpaceWeather.com. "Photos taken between 3:50 a.m. and 4:15 a.m. Bright aurora, with rays of light overhead, almost forming a corona. Beautiful purples came through on the exposures, but only light visible to the eye, as is typical with auroras right before sunrise." Check out LakeSuperiorPhoto.com for more of Malone's work.
Here's a 13-minute recap of three winters' worth of auroral imagery from Sweden. It's all part of "Light Over Lapland: The Aurora Borealis Experience" from Chad Blakley of LightsOverLapland.com on Vimeo. For best results, go full screen and HD. "The movie is a compilation of many thousands of still images captured in Abisko National Park," Blakley writes. "By my calculation I have spent no less than 2,000 hours pointing my camera at the sky recording the northern lights to create this film. ... I am enjoying the midnight sun and all of its warmth, but I am ready for the darkness and the auroras to return."
More auroral glories:
Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.