HAPPY SOLSTICE: Today, seasons are changing. Summer begins in the north; winter begins in the south. With the sun reaching its northernmost point in Earth's sky, one hemisphere will experience the longest day of the year, while the other experiences the longest night. No matter where you live, Happy Solstice! (Note: The exact moment of solstice is 8:32pm PDT on June 20th/03:32 UT on June 21st.)
NOCTILUCENT CLOUDS AT +45oN: Noctilucent clouds (NLCs) have reached mid-latitudes. On June 20th, Eric of Enterprise, Oregon, photographed the first NLCs of summer from latitude +45oN:
"It was a beautiful display," he says.
These are the lowest-latitude NLCs of 2021 so far. The all-time record set in 2019 is +34oN, the same latitude as Los Angeles, CA. Could the clouds descend so far south again? It's possible. Earlier this weekend, the clouds spread across more than half of Europe with sightings in Paris and south of the Italian Alps. Now they are creeping across the mid-latitude mark in North America. Next up: Low latitudes.
NLCs are Earth's highest clouds. They form when summertime wisps of water vapor rise to the edge of space (~83 km high) and crystallize around disintegrated meteoroids. When you see one, you're literally seeing a cloud of frosted meteor smoke.
Observing tips: Look west 30 to 60 minutes after sunset (or before sunrise) when the sun is just below the horizon. If you see luminous blue-white tendrils spreading across the sky, you may have spotted a noctilucent cloud.
Realtime Noctilucent Cloud Photo Gallery
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FARSIDE SOLAR ACTIVITY: The Earthside of the sun is quiet. Stable sunspot AR2833 has not produced a solar flare in more than a week. The farside of the sun may be a different story. Yesterday, something over the sun's horizon hurled a CME into space:
The source of the eruption is probably one of several active regions just around the bend. NASA's STEREO-A spacecraft is monitoring three ultraviolet hotspots on the farside of the sun. Soon (in 2 or 3 days) the spinning motion of the sun will turn them toward us, and we can see which one, if any, is an active sunspot. Stay tuned.
Realtime Space Weather Photo Gallery
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LIMITED EDITION MIRROR KIRK: There are 1000 of these somewhere on Earth ... but only this one has been to the stratosphere. On June 16, 2021, the students of Earth to Sky Calculus launched a limited edition Mirror Kirk onboard their cosmic ray research balloon. Here he is floating 97,234 feet above Mono Lake in central California:
You can have him for $170.10 (the serial number of the Enterprise divided by 10). Modeled after the evil Kirk seen in the classic "Mirror, Mirror" episode of Star Trek (the original series), this 8" statue is made of high-quality polystone resin and expertly painted. It comes with a greeting card showing Kirk in flight and a certificate of authenticity.
To celebrate the 50th anniversary of Star Trek, 1000 Mirror Kirk statues were manufactured and sold at sci-fi conventions in 2016. We've collected a few of these rarities to fly to the stratosphere. Get yours now.
Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education
Realtime Aurora Photo Gallery
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