Uranus and Neptune: Origin, Evolution and Internal Structure

@article{Helled2020UranusAN,
  title={Uranus and Neptune: Origin, Evolution and Internal Structure},
  author={Ravit Helled and N. Nettelmann and Tristan Guillot},
  journal={Space Science Reviews},
  year={2020},
  volume={216},
  pages={1-26}
}
There are still many open questions regarding the nature of Uranus and Neptune, the outermost planets in the Solar System. In this review we summarize the current-knowledge about Uranus and Neptune with a focus on their composition and internal structure, formation including potential subsequent giant impacts, and thermal evolution. We present key open questions and discuss the uncertainty in the internal structures of the planets due to the possibility of non-adiabatic and inhomogeneous… 
The interiors of Uranus and Neptune: current understanding and open questions
TLDR
This review focuses on the things the authors do not know about the interiors of Uranus and Neptune with a focus on why the planets may be different, rather than the same.
The Deep Composition of Uranus and Neptune from In Situ Exploration and Thermochemical Modeling
The distant ice giants of the Solar System, Uranus and Neptune, have only been visited by one space mission, Voyager 2. The current knowledge on their composition remains very limited despite some
Possible In Situ Formation of Uranus and Neptune via Pebble Accretion
The origin of Uranus and Neptune is still unknown. In particular, it has been challenging for planet formation models to form the planets in their current radial distances within the expected
The underexplored frontier of ice giant dynamos
TLDR
Observations of Uranus’ and Neptune’s magnetic fields are summarized and the ingredients for dynamo action in general, and for the ice giants in particular, are discussed, as are the factors thought to control magnetic field strength and morphology.
Could Uranus and Neptune form by collisions of planetary embryos?
The origin of Uranus and Neptune remains a challenge for planet formation models. A potential explanation is that the planets formed from a population of a few planetary embryos with masses of a few
Neptune and Uranus: ice or rock giants?
TLDR
This article considers how observations of Neptune’s atmospheric temperature and composition can provide further constraints and suggests a rock giant provides a more consistent match to available atmospheric observations.
The Promise and Limitations of Precision Gravity: Application to the Interior Structure of Uranus and Neptune
We study the constraining power of a high-precision measurement of the gravity field for Uranus and Neptune, as could be delivered by a low-periapse orbiter. Our study is practical, assessing the
The Case for a New Frontiers–Class Uranus Orbiter: System Science at an Underexplored and Unique World with a Mid-scale Mission
Current knowledge of the Uranian system is limited to observations from the flyby of Voyager 2 and limited remote observations. However, Uranus remains a highly compelling scientific target due to
The imprint of the protoplanetary disc in the accretion of super-Earth envelopes
Super-Earths are by far the most dominant type of exoplanet, yet their formation is still not well understood. In particular, planet formation models predict that many of them should have accreted
Constraining the Effect of Convective Inhibition on the Thermal Evolution of Uranus and Neptune
The internal heat flows of both Uranus and Neptune remain major outstanding problems in planetary science. Uranus’s surprisingly cold effective temperature is inconsistent with adiabatic thermal
...
...

References

SHOWING 1-10 OF 138 REFERENCES
What Do We Really Know about Uranus and Neptune
The internal structures and compositions of Uranus and Neptune are not well constrained due to the uncertainty in rotation period and flattening, as well as the relatively large error bars on the
Thermal evolution of Uranus and Neptune
The brightness of Neptune is often found to be in accordance with an adiabatic interior, while the low luminosity of Uranus challenges this assumption. Here we apply revised equation of state data of
Interior Models of Uranus and Neptune
"Empirical" models (pressure versus density) of Uranus and Neptune interiors constrained by the gravitational coefficients J 2, J 4, the planetary radii and masses, and Voyager solid-body rotation
Uranus and Neptune: Shape and rotation
Giant Planets
We review the interior structure and evolution of Jupiter, Saturn, Uranus and Neptune, and giant exoplanets with particular emphasis on constraining their global composition. Compared to the first
The Interior Structure, Composition, and Evolution of Giant Planets
We discuss our current understanding of the interior structure and thermal evolution of giant planets. This includes the gas giants, such as Jupiter and Saturn, that are primarily composed of
Structure and evolution of Uranus and Neptune
We present three-layer interior models of Uranus and Neptune with central rocky cores, mantles of water, methane, and ammonia (the 'ices'), and outer envelopes primarily composed of hydrogen and
Interior Structure of Neptune: Comparison with Uranus
TLDR
Comparison of shock data with inferred pressure-density profiles for both Uranus and Neptune shows substantial similarity through most of the mass of both planets.
THE FORMATION OF URANUS AND NEPTUNE: CHALLENGES AND IMPLICATIONS FOR INTERMEDIATE-MASS EXOPLANETS
In this paper we investigate the formation of Uranus and Neptune, according to the core-nucleated accretion model, considering formation locations ranging from 12 to 30 AU from the Sun, and with
A COLLISIONLESS SCENARIO FOR URANUS TILTING
The origin of the high inclination of Uranus' spin-axis (Uranus' obliquity) is one of the great unanswered questions about the solar system. Giant planets are believed to form with nearly zero
...
...