SpaceWeather.com Archive — Thu, Jun 20, 2024

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NORTHERN SUMMER BEGINS TODAY: The seasons are changing. This afternoon at 1:51 p.m. PDT, summer begins in the north and winter begins in the south. June 20th is the longest day of the year, or the shortest, depending on your hemisphere. Either way, happy solstice!

SOLAR MAXIMUM NOCTILUCENT CLOUDS: 2024 is supposed to be a bad year for noctilucent clouds (NLCs). High solar activity is warming Earth's upper atmosphere and breaking apart water molecules necessary for noctilucent ice. Yet here they are:

"We observed a beautiful display of NLCs on June 15th," says Harlan Thomas of Carstairs, Alberta. "They lasted for hours."

So far, NLCs are winning their struggle with the sun. They've been seen in Canada and countries in Europe as far south as Poland.

But solar activity isn't the only factor. NLCs form when summertime wisps of water vapor rise to the edge of space, forming a rime of ice around specks of meteor debris. Extra moisture pumped into the atmosphere by the undersea eruption of the Tonga volcano could be giving the clouds an edge. Interhemispheric teleconnections also influence the temperature and moisture available for NLCs.

In short, we just don't know what will happen next. Weeks around the summer solstice often produce the most widespread NLCs, so be alert for electric blue.

more images: from Terry Morris of Birmingham UK; from Marek Nikodem near Szubin, Poland; from Steve Brown of North Yorkshire, UK

Realtime Noctilucent Cloud Photo Gallery
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COLLECTABLE STAR TREK ORNAMENT: No Trekkie Christmas tree is complete without The Arena Ornament. This rare Hallmark keepsake depicts the reptilian Gorn poised to deliver a death blow to Capt. James T. Kirk on the planet Cestus III. On June 14, 2024, it flew to the edge of space onboard a cosmic ray research balloon:

You can have it for $135.95. The ornament depicts a famous scene from The Original Series episode "Arena" first broadcast on January 19, 1967. Decades later, the Gorn have become main villians on the new Star Trek series Strange New Worlds, which we love!

The ornament comes with a Christmas card showing Kirk and the Gorn in flight, and certifying they have traveled to the edge of space and back again.