Noctilucent Clouds Over Hertfordshire

[Knight of Clear Skies]

Took this image when I was out imaging on Thursday night. It took me a long time to realise why there was a bright cloud parked on my eastern horizon, I only heard about the phenomenon recently from this forum and I'd never seen them before.

Just a 10 second exposure with a 50mm lens, taken at about 1:30 in the morning. 

[SnakeyJ]

Great shot - well taken!

[JonH]

Very nice indeed, well done.

[Pete Presland]

beautifull image, very nicely captured. i have been looking out for these most evenings since the beginning of June with no joy, so its nice to see some just down the raod from myself. i thought there was am hint of them Thursday evening though, were these very prominent to the naked eye?

[Knight of Clear Skies]

Thanks everyone, very pleased to see and capture this phenomenon. I find myself wondering how high and far away they are, I'll read up on the subject when I can find the time.

Full capture details: 50mm lens at f4, 10 seconds, ISO 800 with long-exposure noise reduction turned on. Tweaked the settings a little in the Canon software, but I'll have a go at de-noising the sky later and maybe crop it a little.

i thought there was am hint of them Thursday evening though, were these very prominent to the naked eye?

To the naked eye they were prominent white clouds, very easy to spot. However, the structure only showed up when I took the picture.

[tich]

Very nicely done, I saw them a couple of years ago & took a few shots of them but the past 2 seasons I've not seen any so well done.

[robbie c]

Nice image, I was reading up on Noctilucent Clouds the other day as it happens and apparently they are located in the atmospheric layer know as the mesosphere at altitudes between 47 and 53 miles.

At this height these clouds are able to reflect sunlight when the sun is below the horizon, hope that helps  

[Knight of Clear Skies]

I was curious as to how far away the clouds were, so I plate solved the image and looked up the altitude of some of the visible stars on Stellarium.

That's Capella at the top right, I was looking NNE. τ Auriga, where the cloud band transitions from twilight to daylight, was at an apparent altitude of 3.7 degrees and θ Aur, near the bottom, was at 1.4 degrees. Assuming the cloud was 50 miles up, this would put it several hundred miles away if my trig is right.

I can't give an accurate answer, it gets complicated with the curvature of the Earth and atmospheric refraction which makes it possible to look past the horizon, but I think I was looking at clouds somewhere off the west coast of Norway. I find that pretty staggering. Double checking on Google Earth, which has a handy 'show daylight' feature gives a sanity check.

Very nicely done, I saw them a couple of years ago & took a few shots of them but the past 2 seasons I've not seen any so well done.

Thanks very much. There are some other images of them in this forum, on page two. Here's a really nice one.

[markcol]

Lovely shot of an excellent display.

Mark