Summer is starting to cool down in the far north — and that means the northern lights are starting to heat up.
"The midnight sun has set for the final time during the summer season, and the countdown to our first major aurora of the autumn has begun!" Chad Blakley, the photographer behind Lights Over Lapland, writes from Sweden. "My wife and I are traveling in the south of Sweden, and I was able to capture the first minor geomagnetic storm with my camera last night."
Colorful views are also popping up on SpaceWeather.com's real-time aurora gallery — thanks in part to a high-speed solar wind stream that's buffeting Earth's magnetic field. The resulting geomagnetic disturbance is sparking northern lights in Scandinavia, northern Canada and Alaska.
"Last night was the first time I photographed the northern lights since winter," Yukon landscape photographer Jonathan Tucker reported on Twitter. It'll be hard to beat his first effort of the season, which pairs the aurora's greenish glow with orange-tinged clouds.
That alien green comes from the interaction between electrically charged particles from the sun and atoms high up in Earth's atmosphere. This webpage explains the science behind the display, and you can keep track of the auroral forecast by checking in with the National Oceanic and Atmospheric Administration's Space Weather Prediction Center, the center's Facebook page, and NOAA's Ovation maps.
The aurora's green glow blends with the orange glow of light reflected off clouds to produce a colorful scene for late summer near Whitehorse in Canada's Yukon. Feast your eyes on more pictures from photographer Jonathan Tucker's website.
It's easy for Blakley to monitor the fireworks: During the aurora season, it seems as if he's out almost every night, taking pictures and leading tours.
"I have spent the last few months working on a new video project that focuses on the aurora borealis in Abisko National Park, and I am reaching out to share it with you today," Blakley writes. "The film uses a new time-lapse technique that allows me to show you the auroras in a way that I never thought possible — virtual real time. You can see the new film here: https://vimeo.com/70456669. For the best possible viewing experience be sure to watch the film in full screen HD and turn the volume up as high as possible!"
More auroral glories:
Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the NBC News Science Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with NBCNews.com's stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.