A spectacular “storm” of night shiners, the mysterious noctilucent clouds, has been rippling in electric blue waves across the skies of Europe and North America this week.

Science still hasn’t unravelled their origins, and late party leavers may well be asking just what might have been in the “candy”, as these displays have been bright enough to shine right through through the neon haze of major cities.

Noctilucent clouds have been recorded as rare polar and sub solar high altitude clouds since the second half of the 19th century.

But early this decade they started appearing much further south and in much larger volumes than before in late spring and early summer in the northern hemisphere.

NASA has even YouTubed a video complete with a jazzy little song “the cloudy mystery of the 21st century”, which sure beats idiots calling US radio stations proclaiming “It’s a sign, it’s a sign”, which it is, of a country still looking for its marbles.

In fact observations from a special satellite launched to study them, the AIM probe, as well as from the ISS, have found they are closing in on low latitudes, much closer to the equator, than expected.

However they don’t visibly shine in such dramatic fashion in places like Australia because (as the diagram below shows) the sun is too far below the horizon in our middle night skies to reflect off these incredibly tenuous clouds which have been recorded up to 90 kilometres high.

You have to be somewhere closer, say southern Tasmania, to the edges of the long polar days to get this illumination, and besides it rains a lot down there and the party scene is numbered in the dozens.

So, what the hell are night shiners?

Traces of ice crystals have been detected in them. They seem to grow in frequency during solar cycle minimums, except that while the world has been in an unusually deep lull in sunspot activity for the past 2.5 years, they started to invade the skies during the last solar maximum and kept coming back stronger each year.

They may be related to the severe upper atmosphere cooling which is the flip side of the warming caused by the green house gas effect in the lower atmosphere.

But they may also be a sign of rocket launcher pollution, with fine particles of soot providing the nuclei on which water or carbon dioxide ice might form.

And they have been detected above Mars by the European Mars Express orbiter, which has no rocket launches, or parties, or industrial pollution.

So there are no answers yet, but they “sure are pretty.”

Photos by Jan Koeman and Piotr Majewski from  Spaceweather.com