While most clouds form in the troposphere between Earth’s surface and about 11 miles above the ground, these appear in the mesosphere, up to 50 miles high.

Thanks to data from the SPICAM Ultraviolet and Infrared Atmospheric Spectrometer onboard Mars Express, a fleeting layer of clouds have been discovered at an altitude between 80 and 100 kilometres.

Astronomers have observed thick, mineral-rich clouds, potentially containing iron, enveloping the young exoplanet YSES-1b, leading to the possibility of iron rain. The YSES-1 system, only a ...

Around this time, the sun never dips far below the horizon, leaving it well placed to illuminate the high-altitude icy particles as night settles in. Noctilucent clouds most commonly appear ...

Noctilucent clouds over the Baltic Sea, as seen from Germany in 2019. Typically seen in polar regions, the clouds are increasingly appearing at mid- and low latitudes. Matthias Süßen via ...