If there are the most interesting moon races in our solar system, Callisto will be the contender. Jupiter’s second largest moon has a greater impact on its surface than any other planetary body in the solar system, and there are also a lot of ice on the surface.
For decades. Researchers believe that resting on Callisto’s strange surface is a liquid saltwater ocean that spans the entire moon. After carefully studying data from 30 years ago, researchers now have stronger evidence that such oceans do exist.
The team led by Corey J. Cochrane of NASA JPL’s Interior Planets and Geophysical Team is not looking for the ocean on Callisto. According to Cochrane, the team is working on a different project involving scanning Neptune’s Moon Triton to see if it has an underground ocean.
It was a challenge thanks to Triton’s intense ionosphere, which was the last layer before the space began. Since Callisto also has a strong ionosphere, the team decided to test the 30-year-old measurement method performed by the NASA Galileo task. The mission was launched in 1989 and scanned Jupiter and its moons between 1995 and 2003.
Cochrane told CNET in an email.
“We were able to remove this fuzzy plasma noise source from the measurements using previously developed plasma simulations so that signals from the ocean can be analyzed independently,” Cochrane said.
In short, Galileo’s readings were initially difficult to explain due to Callisto’s strong ionosphere. Once Cochrane and his team cleared the readings, they could consider the data, which strongly suggests that there are oceans beneath the appearance of the moon rock.
The ionosphere looks like the ocean
It took a long time to prove the existence of an underground ocean on Callisto, because the powerful ionosphere mimics such an ocean and you will get the reading.
“Nature’s fundamental laws of physics (Faraday’s law of magnetic induction) suggest that if you move a magnet relative to any conductive material (such as copper wire), you will create a current in that wire that is synchronized with the magnet’s motion,” Cochrane explains. “The current will then generate a secondary magnetic field (due to the movement of electrons in the wire) called the induced magnetic field, which exhibits the properties of the conductive material.”
This is also used with planetary institutions, Cochran said. A satellite or planet with enough internal heat can have a liquid saltwater ocean below the surface. These oceans are electrically conductive due to the salt in the water. Therefore, scientists can use magnetometers to measure induced magnetic fields that “preserve ocean properties.” In other words, the ocean can be found based on the magnetic fields they generate.
Because satellites like Jupiter’s Callisto and Neptune’s Triton have a very powerful ionosphere, the magnetometer’s readings become so noisy that it’s hard for researchers to figure out whether they’re looking at an ocean or random noise from the extra energy in the ionosphere. That’s why researchers have been trapped in the potential underground oceans of Callisto for decades.
Next step
Science doesn’t have to wait another 30 years to find evidence. NASA’s Europa Clipper Mission set sail last year and should arrive at Jupiter and its satellites by 2030, while the European Space Agency’s juice mission should arrive in 2031. These two tasks will almost certainly provide Callisto with more research data.
As far as the information they will collect, Cochrane tells us that it is not necessarily a different data. Instead, this is more data.
“Proving the existence of Callisto ocean from the new measurements depends only on the fact that there are more measurements to be analyzed,” Cochrane said. “For every flight that takes place in each task, the magnetometer captures only a small snapshot of the magnetic field environment.”
Cochrane said data from European Clippers and Juice Tasks will help “fill loopholes in Galileo’s mission” in the hope that researchers will eventually prove whether there is an ocean on Callisto. Additional data will also help researchers estimate the thickness of Callisto’s ocean layer and the thickness of the ice shell lies on its top.
Can Carristo have a life?
NASA and the European Space Agency will not send the mission to Jupiter without good reason. One of them is: Europa’s hidden waters are the leader in alien life.
“Europa’s oceans may support life because we know it has the key elements that support it, those are water, basic chemical elements and energy (e.g., heat sources from the inside) to evolve long enough for a while,” Cochrane said. “The Europa Clippers are actually a habitable task (not to be confused with life detection) and it will provide better data to help us answer this question. Until that time, it’s hard to make a comment.”
But in Callisto, there is a growing case in life. It has surprisingly oxygen and no one can figure out what most of the source is. Combined with the possibility of an increasing number of underground oceans, although it remains far from certain things, it is enough evidence to show that when the mission arrives in 2030 and 2031, take a closer look at the Jupiter-Moon.
