No umbrella is protection enough when it comes to the rainfall on the extra-hot exoplanet WASP-76b, where molten iron could be raining from the sky. Hot Jupiters such as WASP-76b are among the most hellish worlds among the stars. Those give scientists new insight into planetary climates and the diverse atmospheric chemistry that can be found in extreme conditions.
The latest analysis of the WASP-76b shows that the day and nighttime climates differ vastly, from super-hot and cloud-free days to iron rain during the night.
Researchers Found Iron Atoms That May Condense Into Clouds
On September 2 and October 30, 2018, researchers from observatories around the globe took data on this particular hot Jupiter, utilizing the capabilities of the ESPRESSO instrument or the Echelle Spectrograph for Rocky Exoplanets and Stable Spectroscopic Observations, at the Very Large Telescope of the European Southern Observatory. This instrument measures the spectrum of the star, which allows them to uncover its elemental composition in somewhat high resolution.
WASP-76b orbits incredibly close to its 10,932 Fahrenheit parent star, completing its year cycle in just 1.81 Earth days. The team’s calculations show a daytime temperature of 4,388 F and a very interesting nighttime phenomenon. When the researchers tried to create a model with the data they got, they saw an intriguing pattern originating from iron atoms, which might form clouds.
WASP-76b Is Hellish Exoplanet Where Iron Rain Could Be Common
The hot temperatures tear down molecules on the surface of the planet, where the temperatures are similar to those of cool stars. The atoms that are generated this way move around slowly and this creates a large difference between day and nighttime temperatures. On the dark side of the planet, the temperatures are much lower, maybe even two-thirds lower than those on the illuminated side. This allows iron to condense into clouds and perhaps rain down on the surface.