Low Sun on the horizon

The Sun and Earth seen from the International Space Station on 24 May 2020. The height of the Sun over the horizon is called the beta angle and its position can influence Space Station operations.

The Atmosphere-Space Interactions Monitor, ASIM, observes lightning from above and tracks the unseen things that are happening above our heads, from gamma ray bursts to elves and sprites. The space-based thunderstorm-hunter outside Columbus monitors Earth at all times, with some exceptions. When spacecraft arrive or leave the Space Station, ASIM is switched off so the sensitive instruments do not get damaged by their bright navigation lights. When the Sun is too low on the horizon its light can saturate ASIM’s sensors too.