Related papers: Scientific rationale for Uranus and Neptune in sit…
The determination of Saturn's atmospheric noble gas abundances are critical to understanding the formation and evolution of Saturn, and giant planets in general. These measurements can only be performed with an entry probe. A Saturn probe…
The formation and evolution of haze layers in planetary atmospheres play a critical role in shaping their chemical composition, radiative balance, and optical properties. In the outer solar system, the atmospheres of Titan and the giant…
Since the Voyager fly-bys of Uranus and Neptune, improved gravity field data have been derived from long-term observations of the planets' satellite motions, and modified shape and solid-body rotation periods were suggested. A faster…
The search for signs of life through the detection of exoplanet atmosphere biosignature gases is gaining momentum. Yet, only a handful of rocky exoplanet atmospheres are suitable for observation with planned next-generation telescopes. To…
This white paper advocates for the inclusion of small, captured Outer Solar system objects, found in the Ice Giant region in the next Decadal Survey. These objects include the Trojans and Irregular satellite populations of Uranus and…
Sub-Neptune planets, with sizes and masses between those of Earth and Neptune, dominate the exoplanet population. Sub-Neptunes are expected to be the most diverse family of the exoplanet population, potentially including rocky gas dwarfs,…
At the far reaches of the outer Solar System, the ice giants remain the last class of planets yet to be studied using orbiters. The 2023-2032 Planetary Science Decadal Survey has underscored the importance of the ice giants in understanding…
Astronomers are debating whether the plentiful "sub-Neptune" exoplanets -- worlds a bit larger than Earth but smaller than Neptune -- are predominantly rocky planets, water-rich "ocean worlds," or gas-enshrouded mini-Neptunes. This question…
The existence of Uranus and Neptune presents severe difficulties for the core accretion model for the formation of ice giant planets. We suggest an alternative mechanism, namely disk instability leading to the formation of gas giant…
From wispy gas giants on the verge of disruption to tiny rocky bodies already falling apart, short-period exoplanets pose a severe puzzle to theories of planet formation and orbital evolution. By far most of the planets known beyond the…
We report relations between inner ($<1$ au) super Earths (planets with mass/radius between Earth and Neptune) and outer ($>1$ au) giant planets (mass $>0.3~M_{\rm J}$, or cold Jupiters) around Sun-like stars, based on data from both…
The intrinsic luminosity of Uranus is a factor of 10 less than that of Neptune, an observation that standard giant planetary evolution models, which assume negligible viscosity, fail to capture. Here we show that more than half of the…
We fit an isothermal oscillatory density model of Neptune's protoplanetary disk to the surviving regular satellites and its innermost ring and we determine the radial scale length of the disk, the equation of state and the central density…
The shapes of fluid planets bear the signatures of rotational flattening and atmospheric flows. Precise knowledge of their shapes and wind profiles may therefore reveal their interior rotation rates. We re-examine this idea for the ice…
Neptune-size exoplanets are less studied as characterizing their atmospheres presents challenges due to their relatively small radius and atmospheric scale height. As the most common outcome of planet formation, these planets are crucial…
The ice giant planets Uranus and Neptune are assumed to contain large amounts of planetary ices such as water, methane, and ammonia. The properties of mixtures of such ices at the extreme pressures and temperatures of planetary interiors…
The Saturn System has been studied in detail by the Cassini-Huygens Mission. A major thrust of those investigations has been to understand how Saturn formed and evolved and to place Saturn in the context of other gas giants and planetary…
The Galileo mission to Jupiter discovered magnetic signatures associated with hidden sub-surface oceans at the moons Europa and Callisto using the phenomenon of magnetic induction. These induced magnetic fields originate from electrically…
The Neptune desert is no longer empty. A handful of close-in planets with masses between those of Neptune and Saturn have now been discovered, and their puzzling properties have inspired a number of interesting theories on the formation and…
Super-Earths, objects slightly larger than Earth and slightly smaller than Uranus, have found a special place in exoplanetary science. As a new class of planetary bodies, these objects have challenged models of planet formation at both ends…