The Extreme ultraviolet lies at the energetic end of the electromagnetic spectrum, between the ultraviolet and X-rays.
EUV light is energetic enough to ionize atmospheric gas and break molecular bonds.
EUV light is absorbed high in planetary atmospheres - in the upper thermosphere and exosphere. Energy input at such high altitudes means gas can be heated to “escape” temperatures - hot enough that individual atoms and ions can escape planetary gravity, or simply that heated gas expands into space beyond the planet’s grasp
Knowledge of EUV radiation from stars in general is currently guesswork and uncertain by factors of 10 or more.
We do not know whether atmospheres survive on other planets.
