(top) A MAJOR OUTBREAK OF NOCTILUCENT CLOUDS: Last night, July 5-6, a major outbreak of noctilucent clouds (NLCs) blanketed Europe. Electric-blue tendrils of frosted meteor smoke rippled over almost every European capital from Scandinavia to the Adriatic. “It was the most phenomenal display of NLCs I’ve seen in my life,” says Viktor Veres, who photographed the outbreak from Budapest, Hungary.
“I was just getting ready for dinner when one of my friends, Alex, cried ‘NLC party time!’,” says Veres. “The electric-blue clouds were almost directly overhead. I sprinted to the car (partially dressing in the street) and drove up Gellért Hill for a view of the clouds over the most famous sights of Budapest–the Danube River, Chain Bridge, Buda Castle, and Parliament. And, yes, my dinner got cold.”
(center) Paris was also “overcast” by noctilucent clouds. “They were very bright,” reports Bertrand Kulik, who shot them floating above the Eiffel Tower.
“The shapes of the noctilucent waves were out of this world!” he says.
NLCs are Earth’s highest clouds. Seeded by meteoroids, they float at the edge of space 83 km above the ground. The clouds form during summer when wisps of water vapor rise up to the mesosphere, allowing water to crystallize around specks of meteor smoke. This summer, record cold temperatures in the mesosphere are boosting their production.
Last night’s mega-display in Europe comes on the heels of a 4th of July sighting in southern California at the same latitude as Los Angeles. It seems that everyone should be alert for noctilucent clouds. Dusk and dawn are the best times to look; here’s why.
(bottom) COMET NEOWISE MEETS NOCTILUCENT CLOUDS: When European astronomers woke up this morning to photograph Comet NEOWISE (C/2020 F3), they saw something they didn’t expect. The sunrise comet was surrounded by noctilucent clouds. Petr Horálek caught the once-in-a-lifetime shot from Seč, Czech Republic.
“Noctilucent clouds crossed the skies like spider webs,” says Horálek. “They are caused by ice crystals on particles of meteoric dust. This dust often comes from comets’ tails. And here we are – both phenomena can be seen in one image as bright Comet NEOWISE is on the left, rising in the glory of morning dawn.”
Similar scenes were observed in Benton City, Washington; Great Falls, Montana; Spicheren, France; Monte Grappa, Italy; Turek, Poland; Čadca, Slovak Republic; Berlin, Germany; and Lublin, Poland. It was a rare morning, indeed.