Noctilucent Clouds on July 5, 2020 @ Budapest, Hungary
© Viktor Veres
Noctilucent Clouds on July 5, 2020 @ Budapest, Hungary
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."

Paris was also "overcast" by noctilucent clouds. "They were very bright," reports Bertrand Kulik, who shot them floating above the Eiffel Tower:

Noctilucent clouds on July 5, 2020 @ Paris
© Bertrand Kulik
Noctilucent clouds on July 5, 2020 @ Paris
"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.