"With the latest Star Wars movie coming out, people are wondering: does extraterrestrial life exist? One way of answering this is through the Cassini Solstice Mission, which has investigated areas around Saturn. Although no life was found, the next step towards answering this should be to study the moons that have the highest possibility of containing life. Certain moons of Jupiter should be analyzed rather than other destinations because they contain elements which can create life which are water, an atmosphere, and tidal effects.
Why are water, an atmosphere, and tidal heating necessary? Water is necessary for life because of its ability to be liquid, gas, and solid, along with its power to dissolve other substances. An atmosphere is necessary because it can protect life from radiation and objects from space and making temperature more consistent. Lastly, tidal effects create heat with the help of gravitational forces from surrounding planets. All three of these necessities exist on Callisto, Europa, and Ganymede.
The first satellite that should be analyzed is Callisto. Callisto is known to be the third largest moon in the Solar System and has already been studied by Voyager 10 and 11. It has been proven that this orbiting terrain has lots of water in existence along with a thin atmosphere consisting of carbon dioxide. Although this moon lacks tidal effects, it is outside of Jupiter's radiation belts which help create an environment similar to Earth which increases the probability of life existing there.
The second satellite that should be studied is Europa. First of all, no other spacecraft has visited Europa, and there is already evidence that water exists there due to cryo geysers and several marks that show the flow of water. A layer of oxygen does exist, although it is created through the dissociation of molecules. Tidal flexing provides the heat and energy which maintains a temperature similar to the one in Earth.
The last moon that should be analyzed is the largest moon that orbits Jupiter; Ganymede. It has a thin layer of oxygen and has an ionosphere and magnetosphere that also has similar qualities of the Ganymede atmosphere. It is believed that it has subsurface oceans. Finally, tidal flexing and its moving plates create and maintain the energy and temperature.
Callisto, Europa, and Ganymede are Jupiter's moons need to be further studied because of the presence of water, atmosphere, and tidal heating, which all can contribute to the possibility of life. Callisto, with lots of water and a thin carbon dioxide layer, Europa, with cryo geysers and a thin oxygen layer, and Ganymede, with moving plates and tidal effects, are the best line-up of moons to analyze to increase the possibility of encountering extraterrestrial life. Considering the fact on how much encountering extraterrestrial life forms would change society, these moons of Jupiter are certainly more compelling targets for the Cassini-Huygens satelite than any other."