NOW IS A GOOD TIME TO SEE MERCURY: When the sun goes down tonight, step outside and look west. See Venus? Now look lower. Mercury is there, too, not far above the horizon. Mercury is having its best evening apparition of the year for northern observers, as shown here, here, and here.
THE SOLAR WIND HAS ARRIVED: Earth is inside a stream of solar wind flowing from a southern hole in the sun's atmosphere. Wind speeds are currently topping 500 km/s--not enough to cause a geomagnetic storm, but sufficient for some beautiful Arctic auroras. Sacha Layos sends this picture from Circle City, Alaska:
"This is my second year of volunteering for the 1,000 mile Yukon Quest's Circle City checkpoint which is nestled deep in interior Alaska close to the Canadian border," says Layos. "The second night I was there, a 22 degree Moon halo appeared above the dog yard. I watched it with joy when the aurora suddenly and briefly picked up! My sleep-deprived eyes sure were happy to see two of my favorite celestial events right above the dog yard where dogs are resting and mushers are tending to them." Aurora alerts: SMS Text.
Realtime Aurora Photo Gallery
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HIGH-ALTITUDE BALLOON PHOTOS OF STRATOSPHERIC CLOUDS: On Jan. 22, 2020, something lucky happened. Spaceweather.com and the students of Earth to Sky Calculus were inside the Arctic Circle, preparing to launch a cosmic ray balloon. Moments before liftoff, an outbreak of Type 2 polar stratospheric clouds (PSCs) started developing over the launch site. PSCs are very rare. They form in the stratosphere only when the air temperature drops to a staggeringly-cold -85C. And they are extremely difficult to catch. Working quickly, we launched two balloons directly into the outbreak.
Operating 4 cameras, the two balloon payloads photographed the clouds from altitudes as high as 75,000 feet. We believe this is the first time polar stratospheric clouds have been photographed by a high-altitude balloon from their own habitat–the stratosphere. The footage reveals beautiful filamentary structures previously unseen from the ground.
How did we get so lucky? We had some help from the polar stratospheric vortex.
The polar stratospheric vortex is a jet stream in the Arctic stratosphere. This winter it has been very strong, bottling up cold air and preventing it from spilling to lower latitudes. Just before we launched on Jan. 22nd, something unexpected happened to the polar vortex. It became elliptical and rotated around, sloshing a mass of super-cold stratospheric air over northern Scandinavia.
This is what the vortex looked like on Jan. 22-23, according to NASA’s Microwave Limb Sounder (MLS):
Note the purple blob over northern Sweden. That’s the cold air. PSCs can form inside the white contours. This animation of MLS data created by Lynn Harvey of the University of Colorado's Laboratory for Atmospheric and Space Physics shows how the vortex evolved during our time in Sweden.
Type 2 polar stratospheric clouds are widely regarded as the most beautiful clouds on Earth. They are made of tiny ice crystals that diffract high-altitude sunlight, glowing with colors so vivid that some people mistake them for "daytime auroras." Earth to Sky student Jordan Herbst’s photos of the Jan. 22-23 outbreak show how they look from the ground. Now we know they’re beautiful from the stratosphere, too.
Stay tuned for more news from our trip to the Arctic Circle.
A sharable version of this story may be found here.
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24K SPACE ROSE FOR VALENTINE'S DAY: On Feb. 1, 2020, the students of Earth to Sky Calculus launched a cosmic ray balloon to the stratosphere. This 24k gold foil-gilded rose went along for the ride. At the apex of the flight, the acrylic bloom was 115,823 feet above the Sierra Nevada mountains of central California:
You can have it for $156.75. The students are selling these roses to support their cosmic ray ballooning program. They make great Valentine's Day gifts. Each one comes with a romantic card showing the rose in flight and telling the story of its journey to the edge of space and back again.
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