New method for calculating tidal effects within planets and moons

Nov. 8 () –

New NASA-funded research has developed a new method to calculate how tides affect the interior of planets and moons.

The study looks at the effects of body tides on objects that do not have a perfectly spherical interior structure, which is an assumption of most previous models.

Body tides refer to the deformations that celestial bodies experience when they interact gravitationally with other objects. Consider how Jupiter’s powerful gravity pulls on its moon Europa. Because Europa’s orbit is not circular, the crushing pressure of Jupiter’s gravity on the moon varies as it travels along its orbit.

When Europa is closer to Jupiter, the planet’s gravity is felt more. The energy from this warp is what heats Europa’s interior, allowing an ocean of liquid water to exist beneath the moon’s icy surface.

“The same is true for Saturn’s moon Enceladus,” says in a statement co-author Alexander Berne of CalTech, affiliated with NASA’s Jet Propulsion Laboratory. “Enceladus has an ice sheet that is expected to be much less spherically symmetric than that of Europa.”

The body tides that celestial bodies experience can affect how worlds evolve over time and, in cases like Europa and Enceladus, their potential habitability for life as we know it. The new study provides a means to more accurately estimate how tidal forces affect the interiors of planets.

The paper also discusses how the study’s results could help scientists interpret observations made by missions to a variety of different worlds, ranging from Mercury to the Moon and the outer planets of our solar system.

The research is published in The Planetary Science Journal.