Planetary scientist Hiroki Karyu and his team at Tohoku University in Sendai City, Japan, have identified the yellowish lower haze in Venus' atmosphere as an accumulation of particles from meteorites. This discovery resolves a mystery surrounding the haze layer, which was first detected by the Venera and Pioneer Venus probes in the 1970s but remained unexplained for decades.
The formation mechanism involves "shooting stars" burning up in the atmosphere and leaving behind cosmic dust. Sulfuric acid then interacts with these particles to create the observed haze. Karyu's research team utilized a microphysical model, which simulates micro-scale processes responsible for cloud and precipitation formation on Earth and other celestial bodies, to determine how the haze forms.
In a study published in Nature Astronomy, Karyu stated that the continuous influx of cosmic dust is sufficient to sustain the lower haze layer, matching the particle size distribution recorded by entry probes. The study further notes that these haze particles of cosmic origin function as efficient condensation nuclei. This process promotes cloud formation in the main cloud deck, even at significant distances from the particles' initial source.