ENTERING THE SOLAR WIND STREAM: Earth is entering a stream of fast-moving solar wind flowing from a large hole in the sun's atmosphere. This is causing the Arctic Circle to glow with green auroras--a hue that could intensify as our planet moves deeper into the stream on Jan. 19th. NOAA forecasters estimate a 60% chance of G1-class geomagnetic storms during the next 24 hours. Free: Aurora Alerts
RARE DOUBLE SUN HALO: Earlier this week, a winter storm passed through Fairbanks, Alaska. In its wake, "it left a lot of ice crystals in the air," says resident Bernard Marschner. "We had a beautiful display of sun halos--including this double halo on Jan. 17th."
The inner ring is a common 22 degree sun halo, caused by sunlight shining through ice crystals shaped like hexagonal prisms. The outer ring is something more exotic.
"It is a 46 degree halo," explains atmospheric optics expert Les Cowley. "They are more rare than many text books and websites would have you believe."
Both 22 and 46 degree halos are caused by the same hexagonal prism ice crystals, but the 46 degree halo is almost always too faint to see. When you see an outer ring, it is usually something else: "A supralateral arc," says Cowley. "These are caused by hexagonal column crystals aligned horizontally in the air and can masquerade as a 46 degree halo."
Marschnet's sighting was the real thing. "We might get more tomorrow with the temperatures supposed to fall to -50 F," he says. Browse the gallery for sightings!
Realtime Space Weather Photo Gallery
VENUS IN A DROP OF WATER: Recipe for a great photo: Splatter a pane of glass with droplets of water. Place the glass in front of the sunset. Point a camera at the droplets and--click!
Photographer John Bell of Haversham, Bucks, UK followed the recipe and obtained the picture above on Jan. 17, 2017.
"I had been looking at macro photos of flowers through droplets and thought I'd try the same with the evening sky," explains Bell. "I taped a photoframe glass to a tree branch in my garden and framed the droplets using my Canon 5D MK2 with a sigma 106mm macro lens. The view was of Venus by a neighbour's tree."
Water droplets act as inverting lenses, so in the original photo the sunset was upside down. "Easily fixed," says Bell, who restored order by rotating the image 180 degrees. "Focusing was a bit difficult," he adds. "After all, water droplets are not perfect lenses." The result, however, was perfectly beautiful. More exposures are available here.
Realtime Space Weather Photo Gallery
FAR-OUT VALENTINE'S GIFT: For the past two years, Spaceweather.com and the students of Earth to Sky Calculus have been launching balloons to keep track of surging cosmic rays in the atmosphere. Our radiation monitoring program receives no support from corporate sponsors or government grants. Instead, we are crowd-funded. To that end, we offer for your consideration a truly far-out Valentine's gift:
On Dec. 18, 2016, the students of Earth to Sky Calculus flew 30 of these pendants to the stratosphere. You can have one for $69.95--including the rose, which has been pressed for safekeeping. Each order comes with a Valentine's card showing the pendant+rose in flight and telling the story of their trip to the stratosphere.
More out of this world gifts may be found in the Earth to Sky store. All proceeds support cosmic ray balloon flights and STEM education.
Realtime Airglow Photo Gallery