Observing Projects

Noctilucent Clouds

Noctilucent Clouds

Noctilucent Clouds (a.k.a. polar mesospheric clouds) are a bright cloud-like phenomenon visible during the deep twilight of summer when the sun is only just below the horizon.

They are the highest clouds, located in the mesosphere around 85km up and are still not fully understood (volcanic debris, space shuttle exhaust plumes and climate change are all candidates) although there is currently a NASA mission studying them.

The observing season usually stretches between late May and early August and the displays can be bright and intricate as is seen in some of the images in my gallery.

2007 Observing Season · 25-26 May · 20-21 June · 27-28 June · 29-30 June (4 Reports)

Other Links and Galleries

29-30th June 2007 · 23:00-01:00 BST

Last night (29-30th June) I observed some moderately bright, structured NLCs in the N-NW sky. I was very tired so didn't venture outside but did take a couple of shots from my landing window which give an impression of this display. The clouds were definitely visible as the twilight finally faded at around 23:00BST and by 00:30BST were visible as is seen here, with two distinctive areas of concentrated clouds forming bright, broad arcing shapes. The display was still visible when I went to bed at 01:00BST.

27-28th June 2007 · 23:30-02:00 BST

Max Altitude: 30 degrees; Azimuth: 330-20 degrees; Brightness: 4; Type: II, III, IV

A call from Andy Ciavarella got me hurrying from my house, camera and tripod in hand, out to the fields south and west of Northallerton where I was able to properly catch this intense display of Noctilucent Clouds. The display was brightest earlier on between 23:30 and 00:00 BST with bright whirls across a more typical banded type of cloud. As I got out into the fields the display changed subtly becoming perhaps less bright, but more extensive, with loops reaching down from the most concentrated area 20 degrees to the East of Capella. I was able to spend time getting some lovely shots of the display which stretched all the way across the Northern to North Western horizon, extending to its highest point approximately 10 degrees west of Capella. As I returned home I watched as a bright looping ribbon formed lower down below the previous extensive region to the East of Capella.

Click for a panorama of the display.

20-21st June 2007 · 00:00-02:00 BST

Max Altitude: 15 degrees; Azimuth: 330-20 degrees; Brightness: 4; Type: IIab, IIIb

On the night of the 20th-21st June the inevitable happened and we got clear skies and a stunning display of Noctilucent Clouds. After a great evening with friends we staked out our new NLC viewing spot up at the college of St Aidan’s and were rewarded with absolutely stunning views of a bright, complex display of clouds in the northern sky. Our estimates placed it up to about 20 degrees altitude and extending round about 60 degrees towards the west. It was a great night and I spent much of it walking the fields outside Durham to get some nice views of the clouds. Sadly by about 2:30 BST the display was starting to fade and so I called it a night, very satisfied with finally bagging a beautiful display.

25-26th May 2007 · 00:30-01:40 BST

Max Altitude: 10 degrees; Azimuth: 340-30 degrees; Brightness: 2; Type: I

I've bagged my first NLCs of the season. These were somewhat lost against the light cloud which was moving through but still bright and well defined in a narrow band above the NW - N horizon. There didn't appear to be any discernible structure besides some faint horizontal banding, although this could have been caused by the tropospheric clouds moving in front.