At 778 million kilometers (483 million miles) from the Sun, Jupiter’s moons are hotter than they actually are.
Most of these extraterrestrials were thought to be Jupiter, but now there is a new theory: they heat up each other.
Jupiter does not act as a roaring campfire of the surrounding moons, but because of its large mass, it pushes its moons away – it generates heat. This is a known effect Tidal heating.
The new model in this latest study looks at warming from moon to moon, finding that their gravitational interplay with each other causes more tides than the planet they orbit.
“This is amazing because the moons are much smaller than Jupiter.” Says planetary scientist Hamish Hay, At the NASA Jet Propulsion Laboratory (JPL). “You wouldn’t expect them to be able to generate such a big tidal response.”
The new discovery is expected to help astronomers learn more about the overall evolution of Jupiter’s lunar system. So far we know of at least 79 Jovian moons. The top four are Io, Europa, Ganymede and Callisto.
Scientists believe these four large moons are large enough to hide oceans of liquid water on their surface, while Io is hot enough to host more than 400 active volcanoes. It is therefore clear that these satellites are prevented from freezing in deep space.
Works by what is called tidal heating Tidal resonance – These moons vibrate at certain frequencies, a phenomenon that occurs everywhere with water, including on Earth.
“Resonance loads heat up,” Says hey. “Basically, if you push an object or system away, it will move at its own natural frequency.
“If you continue to move the system forward at the right frequency, those oscillations become as big as if you were pushing a swing. If you push the swing at the right time, it will be high, but the timing will get the swing wet.”
The researchers are calculating these natural frequencies: Jupiter’s tidal resonances do not match the size of the oceans that these moons are thought to have.
The tidal forces match the current figures of the Moon’s oceans only when the gravitational forces from the moons are added. The team believes that overall tidal heating is sufficient to melt ice and rock within the satellites.
As always with models like this, there are some ess rights deals that are informative – for example, about how stable tidal resonances are.
However, the researchers say that they now have a good foundation for further exploration of this phenomenon, and that the same approach could help identify more oceans in space.
“Ultimately, we want to understand the source of this heat for the impact on the evolution and habitat of many worlds throughout the Solar System and beyond.” Says planetary scientist Anthony Trinh, From the University of Arizona.
The research was published Geophysical Research Letters.