Internal Heat Flux and Energy Imbalance of Uranus
Abstract With its extreme axial tilt, Uranus' radiant energy budget (REB) and internal heat flux remain among the most intriguing mysteries in our solar system. By combining observations with modeling, we present the global REB over a complete orbital period (1946–2030), revealing significant seasonal variations. Despite these fluctuations, the global average emitted thermal power consistently exceeds absorbed solar power, indicating a net energy loss. Assuming no significant seasonal variation in emitted power, we estimate an internal heat flux of 0.078 ± 0.018 W/m 2 by analyzing the energy budget over one orbital period. The combination of internal heat and radiant energies indicates substantial global and hemispheric imbalances, with excesses or deficits exceeding 85% of emitted power at the hemispheric scale. These findings are crucial for understanding Uranus' interior and atmosphere. A future flagship mission to Uranus would provide critical observations to address more unresolved questions of this enigmatic ice giant.
Authors
- Gwenaël Milcareck (ORCID: https://orcid.org/0000-0002-3524-9012)
- Agustín Sánchez-Lavega (ORCID: https://orcid.org/0000-0001-7234-7634)
- S. Pérez‐Hoyos (ORCID: https://orcid.org/0000-0002-2587-4682)
- R. Hueso (ORCID: https://orcid.org/0000-0003-0169-123X)
- Xun Jiang (ORCID: https://orcid.org/0000-0001-8932-3807)
- C. A. Nixon (ORCID: https://orcid.org/0000-0001-9540-9121)
- T. Guillot (ORCID: https://orcid.org/0000-0002-7188-8428)
- Liming Li (ORCID: https://orcid.org/0000-0002-5257-9849)
- Ulyana A. Dyudina
- P. M. Fry (ORCID: https://orcid.org/0000-0002-7367-6541)
- Michael T. Roman (ORCID: https://orcid.org/0000-0001-8206-2165)
- Xinyue Wang
- Cheng Li (ORCID: https://orcid.org/0000-0002-8280-3119)
- Xi Zhang (ORCID: https://orcid.org/0000-0002-8706-6963)
- Robert A. West (ORCID: https://orcid.org/0000-0002-4320-2599)
- Matthew Kenyon
Institutions
- Centre National de la Recherche Scientifique (FR)
- Space Science Institute (US)
- Planetary Science Institute (US)
- Goddard Space Flight Center (US)
- Jet Propulsion Laboratory (US)
- University of Wisconsin–Madison (US)
- University of Leicester (GB)
- University of the Basque Country (ES)
- Université Paris Sciences et Lettres (FR)
- University of Michigan (US)
- Sorbonne Université (FR)
- Lagrange Laboratory (FR)
- Ente Vasco de la Energía (ES)
- Observatoire de la Côte d’Azur (FR)
- University of Houston (US)
Publication Details
- Journal
- Geophysical Research Letters
- Published
- 2025-07-14
- DOI
- https://doi.org/10.1029/2025gl115660
- Citations
- 2
- Primary Topic
- Astro and Planetary Science
- Type
- article
- Field-Weighted Citation Impact
- 2.31
Funders
- National Science Foundation
- National Aeronautics and Space Administration
- Indian Council of Agricultural Research
- Nuclear Safety and Security Commission