PROTONS ARE RAINING DOWN ON EARTH: A solar proton storm is in progress on Aug. 25th as energetic particles from the sun rain down on Earth's upper atmosphere. The proton-rich downpour is coming from a phalanx of active sunspots emerging over the sun's eastern limb. So far this is only a minor event (category S1), posing no threat to astronauts or air travelers. Proton storm alerts: SMS Text
THE FARSIDE SUNSPOTS HAVE ARRIVED: Last week, sunspot groups on the farside of the sun hurled several significant CMEs into space. Here's an example. They're not on the farside anymore. Today, the active regions are turning to face Earth:
Already today, there has been an M4.5-class solar flare from these advancing sunspots (movie), and more are in the offing. The complex structure of the sunspots, especially 4197, is a telltale sign of flare danger. An X-class event this week would not be a surprise. Solar flare alerts: SMS Text
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LATE SEASON NOCTILUCENT CLOUDS--EXPLAINED: Usually the summer season for noctilucent clouds (NLCs) is over by now. Instead, Arctic sky watchers have been seeing some very bright NLCs:
"I caught these late-season NLCs drifting in front of the crescent Moon on Aug. 21st," reports Sebastian Sainio of Björköby, Finland. Almost a thousand kilometers away in Kiruna, Sweden, the clouds were so bright, they "seemed like sunrise," while polar air travelers witnessed dramatic displays from the window seat.
What's going on? Lynn Harvey of the Laboratory for Atmospheric and Space Physics (CU Boulder) found the answer. "There is a beautiful 5-day planetary wave that is driving temperatures over Scandinavia to be ~10 K colder than in other longitude sectors in the last few days," she explains.
This Hovmöller diagram from NASA's microwave limb sounder (MLS) shows the cold wave:
Normally, late August warmth melts away icy NLCs in the mesosphere. The planetary wave, however, has reversed that trend. Cold troughs in the wave freeze water vapor around meteoric dust, seeding these unseasonal night-shining clouds.
The NLCs could reappear at 5-day intervals. That’s because planetary waves--giant atmospheric ripples with natural periods of 2, 5, 10, and 16 days--are the drivers. The 5-day mode is the strongest, a fundamental global oscillation of Earth's atmosphere.
If you live around the Arctic Circle, please be alert for these late-season clouds, and submit your photos here
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LITTLE GREEN SANTA ORNAMENT: You can't buy this on Amazon: The Little Green Santa Christmas Ornamant is only available from the Earth to Sky Store. On Aug. 22, 2025, it flew to the stratosphere onboard a cosmic ray research balloon:
You can have it for $99.95. Hand-sculpted in the USA, this humorous ornament shows Santa arriving from the North Pole of a distant planet. Durable polyresin construction makes it lightweight enough to hang on any tree, but sturdy enough to last for many Christmases to come.
The students are selling space ornaments to pay the helium bill for their cosmic ray ballooning program. Each one comes with a greeting card showing the ornament in flight and telling the story of its trip to the stratosphere and back again.
Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education
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