The Astronomy Picture of the Day (APOD) website has published its daily image dedicated to noctilucent clouds observed over Sweden's territory. This NASA-curated project, which brings together the work of professional astronomers, publishes a daily photograph or image of space with a brief scientific explanation. Noctilucent, or night-shining clouds, form at extremely high altitudes—approximately 80 kilometers above Earth's surface, in the mesosphere, significantly higher than ordinary clouds. They consist of tiny ice crystals and become visible during twilight, when the Sun is just below the horizon, illuminating them from below, while the lower atmospheric layers are already shrouded in shadow. This effect causes the clouds to appear luminous against the dark sky, which is how they earned their name. This phenomenon is most frequently observed at high latitudes, particularly during summer in the Northern Hemisphere, though the exact timing and visibility conditions may vary. Scandinavian countries, including Sweden, are among the regions where astronomy enthusiasts and photographers regularly report observations of noctilucent clouds. The APOD project has, for several decades, acquainted a wide audience with remarkable astronomical and atmospheric phenomena, accompanying visual material with accessible explanations prepared by specialists in the field of astronomy.