In which, as the year comes to its end, our friends and collaborators look back and share their moments:

A few years ago, I wouldn’t have thought that one of my highlights of 2013 would be seeing a type of rare cloud. According to the time stamp on my photograph, it was 1.08am on July 2nd when I found it.

I’d been half-looking for noctilucent cloud for the last two summers. I knew its visibility was limited to more northern latitudes, the weeks around midsummer and late nights, and I knew I had a chance of seeing it because of my location in the Orkney islands and my night work, out doing bird surveys listening for endangered corncrakes.

Noctilucent cloud, literally ‘night shining’, is the highest and one of the rarest types of cloud, drifting in the upper atmosphere, made of ice crystals rather than water droplets. It’s usually invisible but just after sunset around midsummer – in ‘deep twilight’ – the tilt of the earth allows it to catch the last light of the sun.

Sometimes known as ‘space cloud’, it’s a fairly recently discovered meteorological phenomenon. The first recorded observation was in 1885, two years after the eruption of Krakatoa. It could be that the ice crystals have formed around specks of dust – from volcanoes, meteors or space shuttle exhausts. I like the ideas of pollution creating something beautiful.

2013 has, more than any previous year for me, been marked by being alone. I’ve been by myself in the little houses I’ve lived in on the small island of Papa Westray and in the harbour town of Stromness, and in my work writing and doing bird surveys. Sometimes I was lonely but it was what I needed to do and helped me to get to know the islands. The moon, the wind (and the internet) were my friends.

I was out alone in the car when I saw noctilucent cloud for the first time, on a back road in the Stenness area. I’d spent weeks scouring these dark isles for corncrakes, bats, phone reception and rare cloud but my survey period was almost over. If I’d had someone with me and had been chatting, I might not have noticed but, that night, there it was, at the top of my field of vision, unmistakable. Fifty miles high, in the deep twilight, icy blue wisps hung like lightning crossed with cotton wool. I got out of the car and held my phone to the sky, smiling like a nutter. At this time of night most clouds are silhouetted but the space cloud – it shone.

Amy is a regular contributor to Caught by the River. Read her Curious Isles columns here.