An illustration representing how hot Jupiters of different temperatures and different cloud compositions might appear to a person flying over the day side of these planets on a spaceship, based on computer modeling. (NASA/JPL-Caltech/University of Arizona/V. Parmentier)
Understanding the make-up and dynamics of atmospheric clouds is crucial to our interpretations of how weather and climate behave on Earth, and so it should come as no surprise that clouds are similarly essential to learning the nature and behavior of exoplanets.
On many exoplanets, thick clouds and related, though different, hazes have been impediments to learning what lies in the atmospheres and on surfaces below. Current technologies simply can’t pierce many of these coverings, and scientists have struggled to find new approaches to the problem.
One class of exoplanets that has been a focus of cloud studies has been, perhaps unexpectedly, hot Jupiters — those massive and initially most surprising gas balls that orbit very close to their suns.
Because of their size and locations, the first exoplanets detected were hot Jupiters. But later work by astronomers, and especially the Kepler Space Telescope, has established that they are not especially common in the cosmos.
Due to their locations close to suns, however, ...