I know, sounds like a sixties pop group.
It's that time of year again, in fact has been for a little while, for those of us residing in the Hemisphere Northern, especially the more northerer of us.
There used to a site that's long gone that was somewhat European in its patronage (maybe North Americans on the whole just are North enough?).
A more obscure one I eventually found after a gap of a few years turned out to be
Go to latest sightings, postiive reports, and currently June.
From the reported locations you can see how far south folk are picking them up.
Or it'll help you confirm that you did see one if you haven't seen one before.
Here in the UK Scotland fares best, but reports can come in as far south as kent.
They make a change, just remember to look towards where the Sun will rise if you are doing a long nighter in these Solsticial times after you've finished and packed away, especially if you are in an area that's North enough to be deprived of astronomical twilight for a month or three.
They are a somewhat strange cross between electric blue and mother of pearl blue.
And when they are a good set of wavey ones quite distinct from bits of cirrus or contrails that are just catching the rays of the still hidden Sun (the aforementioned colour difference also helps).
They're mesospheric, and they do seem to have increased a bit in the past couple of years, or at least given more spectacular shows at times.
Whether that's the sheer amount of rockets being thrown up nowadays or Solar Maximum, or whatever (the ice crystals need something to seed upon, I believe it is something like the classical supersaturated solution case, but I've been wrong afore, and I promise to be wrong again), it doesn't stop you seeing 'em.
