Tuesday 21 December 2021

Winter Solstice on Cairn Gorm: mist in the glens, strange flowing frost patterns, weird optical illusions (or possibly an invasion from outer space) - updated for explanation of the last


The winter solstice, the turning of the year, leading into celebrations as the sun returns. A day for the hills. The temperature inversion of the last few days continued and I drove to the Cairngorms in bands of dense fog and a temperature of -4C. Then as I climbed out of the frosted landscape and into the sunlit uplands the air warmed. The golden red glow of Cairngorm granite replaced the pale spectral washed-out corries and glens.

Between the mist and the sunlit slopes lower hills were draped in tendrils of frost that looked as though they were flowing, a strange effect I'd not seen before.

From the summit of Cairn Gorm I watched the hills darkening as the sun sank into distant clouds and the sky turned red. 

As I descended the line of hills rising above the mist far to the north-west caught my eye. I couldn't place the strange blocky shapes. Behind them were hazy hints of other objects. What was I looking at? Here are two photos. This is exactly what I saw, not some distortion in the camera.

And here's an enlarged section of the top picture.

As I haven't heard of the Martians landing I'm assuming this is an optical illusion related to the temperature inversion. Unusual and weird, whatever it is. 

Thanks to everyone who commented that the strange shapes are an optical illusion called the Fata Morgana. There's a fascinating explanation on Wikipedia.


  1. Fata Morgana (or something very similar)


  2. Looks like a fata morgana, Chris. Amazing sight! I spent the day in Abernethy and was home just before sunset. Kinda wish I'd stayed out just a little longer now!

  3. Yep, those last pics are a great example of fata morgana. I've seen that on occasion looking out over the Firth of Forth to the Bass Rock and the N Berwick Coast. On one occasion the Bass Rock stood up like a giant skyscraper.

  4. Thanks for the explanation guys. I've never seen one or even heard of fata morgana

  5. Thanks for the explanation everyone. I hadn't come across this phenomenon before.

  6. Fascinating... Extraordinary phenomena. Never heard of them before.