The enigmatic summer phenomenon shining from the edge of space

With no recorded sightings before 1885, noctilucent clouds have been linked to volcanoes, pollution or climate change

As summer arrives in the northern hemisphere, so do the noctilucent clouds – hopefully. These high-altitude formations are as enigmatic as they are beautiful. Their name derives from Latin, meaning “night shining”.

They appear during the summer months and glow with an electric-blue intensity against the darkening western sky. Look for them about half an hour after sunset.