Crucially, unlike the odd magnetic field of IO, it seems to indicate that it masks the fluid value of the ocean, Europa’s own Galileo era magnetic signals remain strong. “In Europa, this is a very clean result,” said Robert Pappalardo, a project scientist at the Jet Propulsion Laboratory. The cold moon is far away from Jupiter and the intense plasma space environment of IO, and Europa’s own magnetic sensing signal “really extends out.”
But if both satellites are tidally heated, why is only Europa with the internal ocean? According to Nimmo, “There is a fundamental difference between a sea of liquid water and a sea of magma. Magma wants to escape; water does not.” Liquid rocks are not as dense as solid rocks, so it wants to rise quickly. The new study shows that its depth inside IO is not enough to hover inside IO to form a large-scale interconnected ocean. However, liquid water is more dense than its solid ice-cold form. “Liquid water is heavy, so it is collected into the ocean,” Sori said.
“I think that’s most of the information in this article,” Sori added. Tidal heating can be difficult to create magma oceans. But on the cold moon, it can easily create a sea of water due to the strange ice density. This shows that living throughout the solar system has many potential habitable environments to call home.
Hell’s poster kids
The revelation of IO’s lack of its shallow magma ocean emphasizes that tidal heating is poorly understood. “We never really understand where the mantle is melting inside IO, how the mantle melting surfaces,” Declay said.
Our own moon also shows evidence of primitive tidal heating. Its oldest crystal was formed by a flow of molten matter 4.51 billion years ago, which was blown up by a huge impact event. However, it seems that a second lava reservoir 4.35 billion years ago formed many lunar crystals. Where did that come from later?
Nimmo and co-authors came up with an idea in a paper published in nature in December: Maybe the moon on Earth is like IO. At that time, the moon was obviously close to the earth, and the gravity field of the earth and the sun were fighting for control. At a certain threshold, when the gravity influences of the two are roughly equal, the moon may temporarily adopt an elliptical orbit and be heated by the gravity kneading of the earth tidal. Its interior may have retreated, leading to a secondary volcanic boom.
However, the exact tidal heating happens to be where the moon is inside, so all melting happens is unclear.
Perhaps if IO is understandable, our moon can do it too—and several other satellites in our solar system with hidden tidal engines. For now, this volcanic ball is still incredible. “IO is a complex beast,” Davis said. “The more we observe, the more complex the data and analysis becomes, the more confusing it becomes.”
ability Reprinted under the permission of Quanta Magazine, an editorially independent publication Simmons Foundation Its mission is to enhance public understanding of science by covering research developments and trends in mathematics and physics and life sciences.
