However, Callisto is a fascinating moon in many respects. First of all, it is the third largest moon in the solar system (after Ganymede and Titan). It is an object only 1 percent smaller than Mercury. It orbits Jupiter at a distance of approximately two million kilometers and always faces the same side, just as the Moon faces the same side towards Earth.
It is worth noting that current estimates indicate that this icy and rocky moon likely contains a layer of subsurface ocean within it. The problem is that this ocean is covered by a layer of ice 200 kilometers thick, so it will remain out of our reach forever. On the other hand, thanks to its distance from Jupiter, it is the only Galilean moon on which a manned base could be established in the distant future. At a distance of two million kilometers from the gas giant, radiation levels no longer pose a danger to humans.
Read also: Here we can find life in space. Jupiter’s moon showed what it can do
However, there are more than four Galilean moons surrounding Jupiter. The number of natural satellites of the gas giant is constantly growing, and will soon exceed the magic hundred. Maybe that’s why there’s not much talk about Callisto. This is a bad decision. Scientists point out that the surface of this moon is the oldest surface in the solar system. The surface covered by smaller and larger impact craters reflects only 17 percent. Light falling on it.
It’s also worth noting that Callisto has a relict atmosphere in which astronomers have long expected to find at least some oxygen. The first information indicating the presence of this element on Callisto was the plasma detected in Jupiter’s magnetosphere by the Pioneer 10 spacecraft that was flying close to it, and almost immediately, scientists decided to check the effect of this plasma on Europa, Ganymede and Callisto. During the study, measurements were made of the number of water molecules that emerged from the icy shells covering these moons by charged particles. The conclusions of these studies were that the ejected water molecules came from electronic excitation and ionization processes occurring within the ice, rather than from directly colliding with charged ions with water molecules. Other research has also shown that bonds in water ice molecules can be broken by the energy provided by charged particles, causing the formation of H molecules.2 And oh2.
These findings convinced astronomers that small amounts of oxygen could be found on Callisto’s surface over time. The problem is that there is much more oxygen on Callisto’s surface, two or three times greater, than can be explained by this process.
Read also: We will go to Jupiter’s icy moons. What will the juice probe tell us?
Scientists point out that even if the moon was 100 percent covered. Water ice (not 10% as currently assumed), would still not be able to produce all the oxygen observed there in the process. All other currently known processes that may be responsible for the formation of oxygen on Callisto also cannot explain its observed abundance. Scientists are currently analyzing the possibility of conducting a comprehensive examination of the Moon with the JUICE probe, which will be in the Jupiter system around 2030. Perhaps the data it collects will shed light on this mysterious oxygen.
Echo Richards embodies a personality that is a delightful contradiction: a humble musicaholic who never brags about her expansive knowledge of both classic and contemporary tunes. Infuriatingly modest, one would never know from a mere conversation how deeply entrenched she is in the world of music. This passion seamlessly translates into her problem-solving skills, with Echo often drawing inspiration from melodies and rhythms. A voracious reader, she dives deep into literature, using stories to influence her own hardcore writing. Her spirited advocacy for alcohol isn’t about mere indulgence, but about celebrating life’s poignant moments.