Jupiter's second largest moon, Callisto, may be hiding an ocean beneath its surface!
For a long time, the moon Callisto was not considered geologically notable. In the 1990s, however, NASA's Galileo spacecraft recorded magnetic measurements that suggested that its icy surface—like that of Europa, another moon of Jupiter—may harbor a salty, liquid ocean .
The moon's strong ionosphere makes extensive exploration of the suspected subsurface ocean difficult, but scientists have speculated that this electrically conductive upper part of the moon's atmosphere might mimic the magnetic signature of a salty, conductive ocean.
See also: China: Flying robot will search for water on the far side of the moon
Now, a research team has re-examined Galileo mission data and, unlike previous studies, incorporated all available magnetic measurements from Galileo's eight close flybys of Callisto. This expanded analysis appears to provide more evidence for the existence of a subsurface ocean on Jupiter's moon.
It is worth noting that the researchers did not limit themselves to re-analyzing the flight data with advanced statistical techniques. They also used computer models of the ionosphere and geophysical properties of the moon to investigate whether a subsurface ocean is compatible with all the available information about Callisto.
According to the findings, the ionosphere alone cannot explain all of the existing observations, but a subsurface ocean in combination with the ionosphere can. By further investigating the possible scenarios that best fit the data, the scientists predicted that the ocean could be tens of kilometers thick, as measured from the top of the liquid to the bottom. It lies beneath a solid shell of ice that can be tens to hundreds of kilometers thick. Beneath the possible ocean lies a rocky interior.
See also: New evidence for the largest crater on the moon!
These findings lay the groundwork for future studies on Callisto with spacecraft, which could confirm or refute the theory of an underground ocean.
The closest measurements will be made by Europa Clipper NASA's and JUICE (Jupiter Icy Moons Explorer) missions, which have already been launched. China's planned Tianwen-4 mission may also observe Callisto.
The existence of a possible ocean could open the way for research regarding the existence of life on Jupiter's moon.
The research paper has been published in the journal AGU Advances.
See also: New research: Can Uranus' moons support life?
With advances in technology and continued research, we may soon uncover more secrets about this enigmatic moon and its potential to host life in our solar system. With each new discovery, we move one step closer to unlocking the secrets of our universe and discovering what exactly might be waiting for us out there!
Source: phys.org
