A microphysical model led by Hiroki Karyu proposes that a continuous influx of cosmic dust can sustain Venus’s lower haze. Published on April 13, 2026, the study finds that the modeled particles have a size distribution consistent with earlier entry-probe observations.
A model links Venus’s lower haze to cosmic dust
Venus’s lower haze is a layer of tiny, nonvolatile particles—particles that resist evaporation—between the planet’s surface and its main cloud deck. The particles observed by entry probes are smaller than a micrometer. The team’s model tests whether fine solid material arriving from space can account for that observed particle-size distribution.
The model finds that a continuous supply of cosmic dust could sustain the haze. That offers a proposed origin for particles whose presence probes had already recorded, and connects the haze to processes higher in Venus’s atmosphere.
How dust-derived particles could help build clouds
The study describes particles of cosmic origin as efficient condensation nuclei: tiny surfaces on which cloud material can condense. In the model, they promote cloud formation in Venus’s main cloud deck.
Cosmic dust, in this context, is fine solid material entering the atmosphere from space. The model connects that incoming material with the haze particles and their role in cloud formation; the reported particle-size match is to earlier probe observations.
Iron is a plausible clue to the ultraviolet absorber
The modeled haze particles are enriched in magnesium and iron. The study identifies iron as a plausible source of Venus’s long-unidentified ultraviolet absorber, a substance associated with the planet’s ultraviolet-dark markings.
A framework for studying thick atmospheres
The authors say the results may inform future studies of planets with thick atmospheres, including gas giants and exoplanets.
