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Title: TIDALLY HEATED TERRESTRIAL EXOPLANETS: VISCOELASTIC RESPONSE MODELS

Abstract

Tidal friction in exoplanet systems, driven by orbits that allow for durable nonzero eccentricities at short heliocentric periods, can generate internal heating far in excess of the conditions observed in our own solar system. Secular perturbations or a notional 2:1 resonance between a hot Earth and hot Jupiter can be used as a baseline to consider the thermal evolution of convecting bodies subject to strong viscoelastic tidal heating. We compare results first from simple models using a fixed Quality factor and Love number, and then for three different viscoelastic rheologies: the Maxwell body, the Standard Anelastic Solid (SAS), and the Burgers body. The SAS and Burgers models are shown to alter the potential for extreme tidal heating by introducing the possibility of new equilibria and multiple response peaks. We find that tidal heating tends to exceed radionuclide heating at periods below 10-30 days, and exceed insolation only below 1-2 days. Extreme cases produce enough tidal heat to initiate global-scale partial melting, and an analysis of tidal limiting mechanisms such as advective cooling for earthlike planets is discussed. To explore long-term behaviors, we map equilibria points between convective heat loss and tidal heat input as functions of eccentricity. For the periodsmore » and magnitudes discussed, we show that tidal heating, if significant, is generally detrimental to the width of habitable zones.« less

Authors:
;  [1]
  1. Earth and Planetary Science Department, Harvard University, 20 Oxford Street, Cambridge, MA 02138 (United States)
Publication Date:
OSTI Identifier:
21392601
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 707; Journal Issue: 2; Other Information: DOI: 10.1088/0004-637X/707/2/1000; Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COOLING; DISTURBANCES; EVOLUTION; FRICTION; HEAT LOSSES; HEATING; JUPITER PLANET; MELTING; ORBITS; PERTURBATION THEORY; QUALITY FACTOR; RHEOLOGY; SATELLITES; SOLAR SYSTEM; DIMENSIONLESS NUMBERS; ENERGY LOSSES; ENERGY TRANSFER; HEAT TRANSFER; LOSSES; PHASE TRANSFORMATIONS; PLANETS

Citation Formats

Henning, Wade G, O'Connell, Richard J, and Sasselov, Dimitar D., E-mail: henning@fas.harvard.ed. TIDALLY HEATED TERRESTRIAL EXOPLANETS: VISCOELASTIC RESPONSE MODELS. United States: N. p., 2009. Web. doi:10.1088/0004-637X/707/2/1000.
Henning, Wade G, O'Connell, Richard J, & Sasselov, Dimitar D., E-mail: henning@fas.harvard.ed. TIDALLY HEATED TERRESTRIAL EXOPLANETS: VISCOELASTIC RESPONSE MODELS. United States. https://doi.org/10.1088/0004-637X/707/2/1000
Henning, Wade G, O'Connell, Richard J, and Sasselov, Dimitar D., E-mail: henning@fas.harvard.ed. 2009. "TIDALLY HEATED TERRESTRIAL EXOPLANETS: VISCOELASTIC RESPONSE MODELS". United States. https://doi.org/10.1088/0004-637X/707/2/1000.
@article{osti_21392601,
title = {TIDALLY HEATED TERRESTRIAL EXOPLANETS: VISCOELASTIC RESPONSE MODELS},
author = {Henning, Wade G and O'Connell, Richard J and Sasselov, Dimitar D., E-mail: henning@fas.harvard.ed},
abstractNote = {Tidal friction in exoplanet systems, driven by orbits that allow for durable nonzero eccentricities at short heliocentric periods, can generate internal heating far in excess of the conditions observed in our own solar system. Secular perturbations or a notional 2:1 resonance between a hot Earth and hot Jupiter can be used as a baseline to consider the thermal evolution of convecting bodies subject to strong viscoelastic tidal heating. We compare results first from simple models using a fixed Quality factor and Love number, and then for three different viscoelastic rheologies: the Maxwell body, the Standard Anelastic Solid (SAS), and the Burgers body. The SAS and Burgers models are shown to alter the potential for extreme tidal heating by introducing the possibility of new equilibria and multiple response peaks. We find that tidal heating tends to exceed radionuclide heating at periods below 10-30 days, and exceed insolation only below 1-2 days. Extreme cases produce enough tidal heat to initiate global-scale partial melting, and an analysis of tidal limiting mechanisms such as advective cooling for earthlike planets is discussed. To explore long-term behaviors, we map equilibria points between convective heat loss and tidal heat input as functions of eccentricity. For the periods and magnitudes discussed, we show that tidal heating, if significant, is generally detrimental to the width of habitable zones.},
doi = {10.1088/0004-637X/707/2/1000},
url = {https://www.osti.gov/biblio/21392601}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 707,
place = {United States},
year = {Sun Dec 20 00:00:00 EST 2009},
month = {Sun Dec 20 00:00:00 EST 2009}
}