Scientists Solve Decades-Old Mystery of Venus’ Lower Haze Layer

For more than fifty years, the origin of Venus’ enigmatic lower atmospheric haze remained one of planetary science’s persistent puzzles. First detected by Venera and Pioneer Venus probes in the 1970s, this yellowish veil puzzled scientists long after the spacecraft transmitted the planet’s first images back to Earth. New research has finally identified the source: an accumulation of particles derived from meteorites.

According to the findings, shooting stars that disintegrate in Venus’ atmosphere deposit cosmic dust. When sulfuric acid in the clouds interacts with these particles, it generates the observed haze. Hiroki Karyu and his team at Tohoku University in Sendai, Japan, utilized a microphysical model to unravel the process. This modeling approach examines the micro-scale mechanisms responsible for cloud formation and precipitation on terrestrial planets and other celestial bodies.

In a study published in Nature Astronomy, Karyu explained that the steady arrival of cosmic dust provides enough material to maintain the lower haze layer, matching the particle size distribution recorded by earlier entry probes. “These haze particles of cosmic origin act as efficient condensation nuclei, promoting cloud formation in the main cloud deck even far from their initial source,” Karyu noted.