Thermal imaging from Scottish Highlands - solstice evening anomaly

Right, I've got something that's been bothering me for weeks. Shot this thermal footage on my FLIR One Pro (cost me £280 last year, so it's decent kit) on the evening of the summer solstice, 20th June, around 22:15 near Glenfinnan in the Scottish Highlands. Weather was clear, visibility excellent, temperature about 8°C.

I was out doing some amateur astronomy when I picked up something on the thermal camera that wasn't on my naked eye observation. There's a perfectly rectangular heat signature moving horizontally across the frame for about 40 seconds, then it just... ceases. No gradual fade-out, just gone. The object isn't giving off enough heat to be an aircraft (I know what those look like), and it's definitely not a balloon or drone.

Thermal signature dimensions appear to be approximately 30-40 metres in length

Has anyone else got experience with FLIR analysis? Would appreciate some expert input before I post this anywhere else. Cheers.

Interesting bit of kit and decent footage quality. The rectangular signature is intriguing. Could you rule out military exercise activity? There's quite a bit of RAF activity up that way. Also, have you checked with local reports - was anyone else observing that evening? Cross-reference helps eliminate coincidence.

Mate, I've been doing thermal analysis for five years now. That's a solid capture. The thing that stands out to me is the abrupt termination - that's not typical of anything conventional I can explain. Definitely post it to the main site. Just be prepared for the debunkers saying it's a bird (it's not) or a trick of the camera. Have you got the raw file?

FLIR equipment picks up all sorts of atmospheric anomalies that our eyes can't see. Before you get too excited, did you check for temperature inversions or weather balloons in the area? Also, 22:15 in June means it's not actually fully dark - could be reflected sunlight creating an artifact? Just asking the boring questions!

This is genuinely fascinating. The solstice timing is interesting too - there's been a pattern of increased UAP activity during astronomical events. I'd suggest doing a FOIA request for any RAF or military exercises that evening. Glenfinnan's not far from some restricted airspace. Brilliant capture though, really brilliant.