Lunar warming: Jupiter’s icy moons warming each other, new research opportunities

Despite being so far away from the Sun, Jupiter’s moons are warmer than they should be! Beautiful, icy moons are known to host oceans of liquid water to keep them warm inside. And on the planet’s innermost moon, Io, the heat is intense which melts the rocks into magma.

Earlier, researchers believed that Jupiter was the sole reason behind most of the heating associated with magma’s IO’s inner ocean, as well as the liquid interiors of its three icy gallillion moons: Europa, Ganymede and Callisto. But now, a new study has found that the Moon – Moon interaction may be more responsible for heating than the gas giant.

Essentially, researchers have found that moons collide with each other gravitationally and create friction – a process known as tidal heat – while Jupiter stretches itself and squeezes them. Tidal heat is that which causes the interior of the moons to heat up and is driven by a phenomenon called the resonance of the tides.

“It’s surprising because the moons are much smaller than Jupiter,” said the paper’s lead author, Hamish Hay, a postdoctoral fellow at the Jet Propulsion Laboratory in Pasadena, California. “You wouldn’t expect them to be able to create such a huge tide response.”

However, they do.

For any moon to experience tidal resonance, their oceans must be tens to hundreds of kilometers thick. Incidentally, the oceans on Jupiter’s moons are so thick, that the impact of the planet alone is unable to produce tides with the right frequency to resonate with the moons. It was only when researchers added to the gravitational effects of other moons that they began to see tidal forces approaching the moon’s natural frequencies.

As the tides generated by other moons resonate with the lunar frequency, they serve as an energy source and excite subsurface lunar oceans near their natural frequencies. This leads to the generation of fast-flowing tidal waves, which effectively release significant amounts of heat into the oceans and crusts of Ayo and Europa.

Subsequently, these moons begin to experience higher temperatures due to Jupiter alone, and in extreme cases, it may also be the result of melting of ice or rock internally, especially on IO.

However, this current model operates on the assumption that tidal resonance never occurs at its peak. In future studies, Haye and his team of researchers intend to see what happens when they lift that barrier, and also study the true depth of the oceans within these moons.

All, the whole picture of how these moons affect each other is important, as it can shed light on how Jupiter’s marvelous lunar system evolved overall, and also improves our understanding That how the sea world develops in compact systems.

The findings of this study were published in the journal Geophysical research paper, And they can be accessed here.


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