Last night, sky watchers in Europe witnessed the finest display of noctilucent clouds (NLCs) so far this year. Electric-blue tendrils spread as far south as France:
© Alexandre Croisier

"I could see the NLCs from my window," says photographer Alexandre Croisier of Brittany, France. "So I rushed down to the beach to take this picture--a 6 second exposure with my Canon 350D."

In England, the same display stretched from horizon to horizon. "There was quite a lot of detail visible, including swirls and tiger stripes," reports Mark Jones of Leamington Spa, UK. Even city lights did not overwhelm the NLCs. "I had no trouble seeing them from southwest London," says onlooker Maurice Gavin.

July is often the best month of the year to see these mysterious clouds. High-latitude sky watchers should be alert for electric blue in the nights ahead.

More images: from George Kristiansen of Lincolnshire, UK; from Andrew J. Brown of Chelmsford Essex England UK; from Richard Fleet of Pewsey Vale, Wiltshire, England; from Dave Threlkeld of Selsey, West Sussex, UK; from Paul Money of Close to Horncastle, Lincolnshire, UK; from Jorge Sereno of Middlburg, The Netherlands; from Jason Evans of Eastleigh, Hampshire, United Kingdom; from Chris Lloyd of Kidderminster, Worcs. UK; from Pete Glastonbury of Devizes, Wiltshire, UK; from Gordon Fiander of Sheffield, South Yorkshire, England; from Katherine Leadbetter of Bedhampton, Hampshire, UK; from Keith Cooper of Leicester, England; from Jeff Stevens of Stoke-on-Trent, Staffordshire, England;