Astrophysics (Index)About

tidal heating

(tidal working, tidal flexing)
(heating due to friction from motions caused by tidal force)

Tidal heating is heating from friction due to movements within a body due to tidal forces. The process is also called tidal working or tidal flexing. Tidal heating is one of the sources of heat in a body undergoing tidal force, for example, providing the heat to allow liquid water to exist in some solar system moons even though they are at sufficient distance that sunlight would provide insufficient heat.

Such tidal forces and heating occur if a body is not tidally locked with a body it is orbiting, resulting in different parts of it facing the other body, thus being closest to it, over time. It occurs when gravity is pulling significantly more on the portions of the bodies nearest each other, affecting the balance of forces that hold each body together, to the point that the bodies change shape by shifting mass. (Ocean tides are an example of such shifted mass, sea water displaced to the extent that the changes are easily discerned.) This shifting within each body is subject to friction and its resulting heating. If the same side of a body faces the other, then its internal mass is not shifting, but often this is not the case, and any eccentricity in the orbit results in at minimum a small change in which side faces the other body. Orbital resonances tend to increase or maintain such eccentricity, which, for example, has given some moons of Jupiter and Saturn sufficient warmth to harbor subsurface liquid water.


(physics,gravity,tidal)
Further reading:
https://en.wikipedia.org/wiki/Tidal_heating
https://www.esi.utexas.edu/files/078-Learning-Module-What-is-Tidal-Heating.pdf
http://astronomy.nmsu.edu/candaceg/Europa/Tidal_Heating.html
https://tobyrsmith.github.io/Astro150/Tutorials/TidalHeat/
https://www.astro.uvic.ca/~jwillis/teaching/astr201/maths.7.tidal_heating.pdf

Referenced by pages:
Europa
faint young Sun paradox
habitable zone (HZ)
inflated radii
radiation zone
tidal force
tidal migration

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