How to photograph NLCs for science

Noctilucent clouds are fleeting and mysterious - if you catch them, your data can be useful

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Noctilucent cloud season will be in full swing by the time you're reading this. Unfortunately, this doesn't guarantee displays, but rather indicates a period when displays are more likely. Despite being around 80km (50 miles) up in the atmosphere, from the UK they typically appear low above northerly horizons. But this isn't always the case and there have been sightings of them fairly high in the sky. In addition, their apparent altitude and azimuth aren't fixed and can change throughout the night, sometimes showing major changes either in the early period of the display or just before dawn truncates their visibility.

Most low-light imaging equipment, including smartphones with night-capture modes, can record them, and doing so has become something of a summer 'sport'. One major plus at this time of year is that an all-night NLC watch doesn't take that long, allowing you plenty of time to observe them and get some sleep into the bargain.

Recording NLCs in a way that's scientifically useful is surprisingly easy to do. Showing how a display first appears and morphs throughout the night is very valuable, as is revealing how NLCs change at the end of the viewing session as dawn approaches.

The key things that need to be recorded are the structures and relative intensities of the display, as well as how extensive they are and how high they go (their altitude in degrees). With a bit of thought, photographs can show most of these attributes by default, with just the relative intensity being subjective and requiring some degree of calibration.