Abstract

Uranus and Neptune are the archetypes of ice giants, a class of planets that may be among the most common in the Galaxy. They hold the keys to understand the atmospheric dynamics and structure of planets with hydrogen atmospheres inside and outside the solar system; however, they are also the last unexplored planets of the Solar System. Their atmospheres are active and storms are believed to be fueled by methane condensation which is both extremely abundant and occurs at low optical depth. This means that mapping temperature and methane abundance as a function of position and depth will inform us on how convection organizes in an atmosphere with no surface and condensates that are heavier than the surrounding air, a general feature of giant planets. Owing to the spatial and temporal variability of these atmospheres, an orbiter is required. A probe would provide a reference atmospheric profile to lift ambiguities inherent to remote observations. It would also measure the abundances of noble gases which can be used to reconstruct the history of planet formation in the Solar System. Finally, mapping the planets' gravity and magnetic fields will be essential to constrain their global composition, atmospheric dynamics, structure and evolution. An exploration of Uranus or Neptune will be essential to understand these planets and will also be key to constrain and analyze data obtained at Jupiter, Saturn, and for numerous exoplanets with hydrogen atmospheres.

Highlights

  • Introduction“ice giants” form a yet not well-defined class of planets between a few times the mass of the Earth and a fraction of that of Saturn

  • “ice giants” form a yet not well-defined class of planets between a few times the mass of the Earth and a fraction of that of Saturn. Their name comes from the idea that their mass mostly originates from condensed water ice that accreted in protoplanetary disks

  • The large amount of water ice led them to become more massive than traditional terrestrial planets but yet without accreting so much hydrogen and helium to fall into the realm of the larger "gas giants"

Read more

Summary

Introduction

“ice giants” form a yet not well-defined class of planets between a few times the mass of the Earth and a fraction of that of Saturn. The large amount of water ice led them to become more massive than traditional terrestrial planets but yet without accreting so much hydrogen and helium to fall into the realm of the larger "gas giants" This idea is plausible, because water is the most abundant condensable species and certainly the most crucial building block of planet formation[1]. Contrary to all other planets in the solar system, they have only been visited for a couple of days each and from a distance by the Voyager 2 spacecraft flybys Both Uranus and Neptune are fascinating planets that hold some of the keys to understand the origin of our Solar System and to make sense of the observations of exoplanetary atmospheres. We advocate that the exploration of our Solar System must continue and that either Uranus or Neptune, or both, should be the targets in this journey that will help us to understand exoplanets as well

Keys to understanding hydrogen atmospheres
Exoplanets: an expanding dataset
Keys to the formation of giant planets
Findings
Conclusion
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.