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Related papers: What do we Really Know about Uranus and Neptune?

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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 lifetime of the solar nebula. In this paper, we…

Earth and Planetary Astrophysics · Physics 2022-05-25 Claudio Valletta , Ravit Helled

Uranus and Neptune are commonly considered ice giants, and it is often assumed that, in addition to a solar mix of hydrogen and helium, they contain roughly twice as much water as rock. This classical picture has led to successful models of…

Earth and Planetary Astrophysics · Physics 2024-07-11 Uri Malamud , Morris Podolak , Joshua Podolak , Peter Bodenheimer

The origin of Uranus and Neptune has long been challenging to explain, due to the large orbital distances from the Sun. After a planetary embryo has been formed, the main accretion processes are likely pebble, gas and planetesimal…

Earth and Planetary Astrophysics · Physics 2023-10-03 Linn E. J. Eriksson , Marit A. S. Mol Lous , Sho Shibata , Ravit Helled

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 Earth masses which formed beyond Saturn's…

Earth and Planetary Astrophysics · Physics 2021-01-20 Alice Chau , Christian Reinhardt , André Izidoro , Joachim Stadel , Ravit Helled

The origins of Uranus and Neptune are not fully understood. Their inclined rotation axes -- obliquities -- suggest that they experienced giant impacts during their formation histories. Simulations modeling their accretion from giant impacts…

Earth and Planetary Astrophysics · Physics 2024-12-05 Leandro Esteves , André Izidoro , Othon C. Winter

It has been a common assumption of interior models that the outer planets of our solar system are convective, and that the internal temperature distributions are therefore adiabatic. This assumption is also often applied to exoplanets.…

Earth and Planetary Astrophysics · Physics 2019-06-05 Morris Podolak , Ravit Helled , Gerald Schubert

Probing the interiors of the gas giant planets in our Solar System is not an easy task. It requires a set of accurate measurements combined with theoretical models that are used to infer the planetary composition and its depth dependence.…

Earth and Planetary Astrophysics · Physics 2018-12-19 Ravit Helled

Neptunes and sub-Neptunes are typically modeled under the assumption that the interior is adiabatic and consists of distinct layers. However, formation models indicate that composition gradients can exist. Such composition gradients can…

Earth and Planetary Astrophysics · Physics 2026-03-03 Mark Eberlein , Ravit Helled

Venus' mass and radius are similar to those of Earth. However, dissimilarities in atmospheric properties, geophysical activity and magnetic field generation could hint towards significant differences in the chemical composition and interior…

Earth and Planetary Astrophysics · Physics 2021-12-10 Oliver Shah , Ravit Helled , Yann Alibert , Klaus Mezger

Exoplanet characterization is one of the main foci of current exoplanetary science. For super-Earths and sub-Neptunes, we mostly rely on mass and radius measurements, which allow to derive the body's mean density and give a rough estimate…

Earth and Planetary Astrophysics · Physics 2021-06-16 J. F. Otegi , C. Dorn , R. Helled , F. Bouchy , J. Haldemann , Y. Alibert

The formation mechanisms of the ice giants Uranus and Neptune, and the origin of their elemental and isotopic compositions, have long been debated. The density of solids in the outer protosolar nebula is too low to explain their formation,…

Earth and Planetary Astrophysics · Physics 2015-06-22 M. Ali-Dib , O. Mousis , J. -M. Petit , J. I. Lunine

Uranus' bulk composition remains unknown. Although there are clear indications that Uranus' interior is not fully convective, and therefore has a non-adiabatic temperature profile, many interior models continue to assume an adiabatic…

Earth and Planetary Astrophysics · Physics 2024-01-23 Benno A. Neuenschwander , Simon Müller , Ravit Helled

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 hydrogen, helium, and water and compute…

Earth and Planetary Astrophysics · Physics 2019-12-04 Ludwig Scheibe , Nadine Nettelmann , Ronald Redmer

The hundreds of exoplanets that have been discovered in the past two decades offer a new perspective on planetary structure. Instead of being the archetypal examples of planets, those of our Solar System are merely possible outcomes of…

Earth and Planetary Astrophysics · Physics 2015-06-18 David S. Spiegel , Jonathan J. Fortney , Christophe Sotin

Uranus and Neptune are the last unexplored planets of the Solar System. I show that they hold crucial keys to understand the atmospheric dynamics and structure of planets with hydrogen atmospheres. Their atmospheres are active and storms…

Earth and Planetary Astrophysics · Physics 2021-12-08 Tristan Guillot

The low luminosity of Uranus is a long-standing challenge in planetary science. Simple adiabatic models are inconsistent with the measured luminosity, which indicates that Uranus is non-adiabatic because it has thermal boundary layers…

Earth and Planetary Astrophysics · Physics 2020-01-15 A. Vazan , R. Helled

The core accretion theory of planet formation has at least two fundamental problems explaining the origins of Uranus and Neptune: (1) dynamical times in the trans-Saturnian solar nebula are so long that core growth can take > 15 Myr, and…

Earth and Planetary Astrophysics · Physics 2015-05-14 Sarah E. Dodson-Robinson , Peter Bodenheimer

There are now many known exoplanets with Msin(i) within a factor of two of Neptune's, including the transiting planets GJ436b and HAT-P-11b. Planets in this mass-range are different from their more massive cousins in several ways that are…

Earth and Planetary Astrophysics · Physics 2014-11-20 David S. Spiegel , Adam Burrows , Laurent Ibgui , Ivan Hubeny , John A. Milsom

The internal structure of gas giant planets may be more complex than the commonly assumed core-envelope structure with an adiabatic temperature profile. Different primordial internal structures as well as various physical processes can lead…

Earth and Planetary Astrophysics · Physics 2016-10-05 A. Vazan , R. Helled , M. Podolak , A. Kovetz

Voyager 2 observations revealed that the internal luminosity of Neptune is an order of magnitude higher than that of Uranus. If the two planets have similar interior structures and cooling histories, the luminosity of Neptune can only be…

Earth and Planetary Astrophysics · Physics 2015-10-21 Sarah E. Dodson-Robinson