QUIET WEEKEND: Solar activity is low this weekend as multiple sunspots are in decay and pose no threat for strong solar flares. NOAA forecasters say the chance of M- or X-class flares is no more than 1%. Aurora alerts: SMS Text.
AURORA DUNES OVER SAND DUNES: For a few hours during last month's severe geomagnetic storm, the sky mirrored the Earth. "On March 23rd, I photographed aurora dunes over the Sleeping Bear Dunes in Michigan's lower peninsula," reports Ethan Hohnke of Empire, Michigan:
"At first I wasn't quite sure what I captured, other than knowing I was seeing something I hadn't seen before," Hohnke.
He's not alone. Many people are unaware of "aurora dunes," a form of Northern Lights that was identified by researchers only a few years ago. Named after their resemblence to terrestrial sand dunes, aurora dunes are a "mesospheric bore." This is a type of atmospheric gravity wave that springs up from Earth's surface and gets caught in a thermal waveguide ~100 km high. When solar wind particles rain down on the bore, they illuminate its rippling structure:
Sky watchers in the Arctic have been seeing dunes for years without understanding what they were. A breakthrough came on Oct. 7, 2018, when multiple groups photographed dunes from widely separated locations in Finland. Triangulation revealed the dunes to be ~100 km high with a pure, sinusoidal wavelength of about 45 km.
This is a new field of study with potential for discovery. Monitoring aurora dunes may reveal previously hidden waves and waveguides at the boundary between Earth and space. If you see any, submit your photos here.
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FARSIDE SOLAR ACTIVITY: Over the weekend multiple CMEs have flown away from the farside of the sun including this faint halo event on April 1st:
What makes it a "halo" CME? It surrounds the sun on all sides. Halo CMEs may be either coming directly toward Earth or flying directly away. Both geometries result in a 360 degree halo. In this case there was no explosion on the quiet Earthside of the sun, so it must be a farside event.
This CME and several others that appeared over the weekend suggest that the farside of the sun is currently more active than the Earthside. The source of the blasts will turn to face our planet in the next week to 10 days. Solar flare alerts: SMS Text.
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OCEAN BLUE CRYSTAL DOLPHIN PENDANT: Are you looking for a far-out gift? Consider the Ocean Blue Crystal Dolphin Pendant. It flew to the stratosphere onboard a cosmic ray research balloon:
You can have it for $199.95. The students of Earth to Sky Calculus are selling these crystal cetaceans to support their cosmic ray monitoring program.
The dolphin is wrapped in a sterling silver wave and suspended from a matching 18-inch chain. It contains no nickel, no lead, no cadmium; the pendant is totally hypoallergenic. Each pendant comes with a greeting card showing the dolphin in flight, and telling the story of its trip to the edge of space and back again.
Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education
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