The Atmosphere–Space Interactions Monitor, or ASIM, is installed outside the European space laboratory Columbus to monitor electric events at high altitudes.

For years, their existence has been debated: elusive electrical discharges in the upper atmosphere that sport names such as red sprites, blue jets and elves. Reported by pilots, these ‘transient luminous events’ are difficult to study as they occur above thunderstorms.

Satellites have probed them and observations have even been made from mountain tops but their viewing angle is not ideal for gathering data on large scales. In contrast, the International Space Station’s low orbit covers a large part of Earth along the equator and is ideally placed to capture the sprites and jets.

In 2015 ESA astronaut Andreas Mogensen managed to record many kilometre-wide blue flashes around 18 km altitude, including a pulsating blue jet reaching 40 km. A video recorded by Andreas as he flew over the Bay of Bengal at 28 800 km/h on the Station shows the electrical phenomena clearly – a first of its kind.