University of California, Berkeley | 2020 May 26
Giant planets in our solar system and circling other stars have exotic clouds unlike anything on Earth, and the gas giants orbiting close to their stars — so-called hot Jupiters — boast the most extreme.
A team of astronomers from the United States, Canada and the United Kingdom have now come up with a model that predicts which of the many types of proposed clouds, from sapphire to smoggy methane haze, to expect on hot Jupiters of different temperatures, up to thousands of degrees Kelvin.
Surprisingly, the most common type of cloud, expected over a large range of temperatures, should consist of liquid or solid droplets of silicon and oxygen, like melted quartz or molten sand. On cooler hot Jupiters, below about 950 Kelvin (1,250 degrees Fahrenheit), skies are dominated by a hydrocarbon haze, essentially smog.
The model will help astronomers studying the gases in the atmospheres of these strange and distant worlds, since clouds interfere with measurements of the atmospheric composition. It could also help planetary scientists understand the atmospheres of cooler giant planets and their moons, such as Jupiter and Saturn’s moon Titan in our own solar system. ...
Aerosol Composition of Hot Giant Exoplanets Dominated
by Silicates and Hydrocarbon Hazes ~ Peter Gao et al
- Nature Astronomy (online 25 May 2020) DOI: 10.1038/s41550-020-1114-3
- arXiv.org > astro-ph > arXiv:2005.11939 > 25 May 2020