Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer).
Giant planets are large planets, typically 10 or more times the mass of Earth, made predominantly of liquid or gas, notably hydrogen and helium. There are four giants in the solar system: Jupiter, Saturn, Uranus and Neptune.
Radiant energy budgets and internal heat play a key role in the evolution of planets. Here, the authors analyze data from the Cassini mission to show that Jupiter’s radiant energy and internal heat budgets are significantly larger than previous estimates.
Cosmochemical evidence is used to constrain models of Jupiter formation, which unfolds in three distinct phases: a rapid pebble accretion during the first Myr, followed by a slower growth controlled by larger planetesimals, ending in a runaway gas accretion stage.
The Cassini spacecraft has provided an unprecedented characterisation of seasonal changes on Saturn. Here the authors describe the development of a warm polar vortex in Saturn’s northern summer, and show that the hexagon extends hundreds of kilometres from the troposphere into the stratosphere.
Observations of Jupiter’s magnetosphere provide opportunities to understand how magnetic fields interact with particles. Here, the authors report that the chorus wave power is increased in the vicinity of Europa and Ganymede. The generated waves are able to accelerate particles to very high energy.
A dark, ribbon-like structure at Jupiter’s magnetic equator marks a depletion of ionospheric H3+ caused by a lack of photoelectrons. These photoelectrons, which collide with molecular hydrogen to form H3+, are deviated away by magnetic field lines.
A magnetic reconnection event within Saturn’s magnetosphere, captured by Cassini at an unexpected site, may reshape our views on how internally produced plasma is circulated in giant planet magnetospheres.
The Juno spacecraft has detected unprecedented numbers of ‘whistlers’ and ‘sferics’ in its orbits around Jupiter, both indications of high lightning flash rates in the atmosphere of the gas giant planet.
With moons holding subsurface oceans, the outer planets are back in focus as the most promising places to find life beyond Earth. In addition to future missions, ongoing data analysis from past missions has an important role to play.
Hydrogen sulfide gas is detected above Uranus’s main cloud deck, confirming the prevalence of H2S ice particles as the main cloud component and a strongly unbalanced nitrogen/sulfur ratio in the planet's deep atmosphere.