Researchers from Tohoku University, led by Hiroki Karyu, have identified the origin of the mysterious haze layer on Venus. Using a microphysical model, the team determined that the haze is composed of cosmic dust particles resulting from meteorites burning up in the planet's atmosphere.
The study, published in Nature Astronomy, explains that sulfuric acid condenses on these meteorite particles. This process mirrors cloud formation on Earth, where water vapor condenses around aerosol nuclei. The research effectively ruled out volcanic ash and surface dust as the primary sources for the haze.
The findings also resolved the long-standing mystery regarding the absorption of ultraviolet rays in the Venusian atmosphere. The team confirmed that iron sulfate, a compound found in meteorites, matches the properties of the haze particles and acts as the ultraviolet absorber.
At altitudes between 40 and 50 kilometers, a nucleation barrier prevents sulfuric acid from sticking to particles. These particles are instead transported to the upper cloud layer by convection. The study suggests that cosmic dust plays a significant role in the climates of other planets, including gas giants like Jupiter, Saturn, and Neptune.
