From Earth we can see only the near side of the Moon, because of tidal locking.
Is there tidal locking for every moon of other planets in the solar system, too? E.G. for Saturn?
Here is Wikipedia entry for tidal locking: https://en.wikipedia.org/wiki/Tidal_locking
Thank you.
No.
Saturn has many tidally locked moons but many more moons that are not tidally locked.
Being tidally locked is a feature very common in regular moons of planets.
In astronomy, a regular moon is a natural satellite following a relatively close and prograde orbit with little orbital inclination or eccentricity. They are believed to have formed in orbit about their primary, as opposed to irregular moons, which were captured.
There are at least 57 regular satellites of the eight planets: one at Earth, eight at Jupiter, 23 named regular moons at Saturn (not counting hundreds or thousands of moonlets), 18 known at Uranus, and 7 small regular moons at Neptune (Neptune's largest moon Triton appears to have been captured). It is thought that Pluto's five moons and Haumea's two were formed in orbit about those dwarf planets out of debris created in giant collisions.
Most regular moons are known to be tidally locked to their parent planet; the one known exception is Saturn's Hyperion, which exhibits chaotic rotation.
https://en.wikipedia.org/wiki/Regular_moon
In astronomy, an irregular moon, irregular satellite or irregular natural satellite is a natural satellite following a distant, inclined, and often eccentric and retrograde orbit. They have been captured by their parent planet, unlike regular satellites, which formed in orbit around them. Irregular moons have a stable orbit, unlike temporary satellites which often have similarly irregular orbits but will eventually depart. The term does not refer to shape as Triton is a round moon, but is considered irregular due to its orbit.
Regular satellites are usually tidally locked (that is, their orbit is synchronous with their rotation so that they only show one face toward their parent planet). In contrast, tidal forces on the irregular satellites are negligible given their distance from the planet, and rotation periods in the range of only ten hours have been measured for the biggest moons Himalia, Phoebe, Sycorax, and Nereid (to compare with their orbital periods of hundreds of days). Such rotation rates are in the same range that is typical for asteroids. Triton, being much larger and closer to its parent planet, is tidally locked.
https://en.wikipedia.org/wiki/Irregular_moon
So regular moons are almost always tidally locked to their planets, while irregular moons are almost never tidally locked to their planets.
Twenty-four of Saturn's moons are regular satellites; they have prograde orbits not greatly inclined to Saturn's equatorial plane.[7]
The remaining fifty-nine, with mean diameters ranging from 2 to 213 km (1 to 132 mi), are irregular satellites, whose orbits are much farther from Saturn, have high inclinations, and are mixed between prograde and retrograde.
https://en.wikipedia.org/wiki/Moons_of_Saturn
It would seem reasonable that Hyperion is not not tidally locked to Saturn since its orbit is beyond the orbits of the tidally locked moons. Except that one tidally locked moon, Iapetus, orbits beyond the orbit of Hyperion.
The Voyager 2 images and subsequent ground-based photometry indicated that Hyperion's rotation is chaotic, that is, its axis of rotation wobbles so much that its orientation in space is unpredictable. Its Lyapunov time is around 30 days.[21][22][23] Hyperion, together with Pluto's moons Nix and Hydra,[24][25] is among only a few moons in the Solar System known to rotate chaotically, although it is expected to be common in binary asteroids.[26] It is also the only regular planetary natural satellite in the Solar System known not to be tidally locked.
Hyperion is unique among the large moons in that it is very irregularly shaped, has a fairly eccentric orbit, and is near a much larger moon, Titan. These factors combine to restrict the set of conditions under which a stable rotation is possible. The 3:4 orbital resonance between Titan and Hyperion may also make a chaotic rotation more likely. The fact that its rotation is not locked probably accounts for the relative uniformity of Hyperion's surface, in contrast to many of Saturn's other moons, which have contrasting trailing and leading hemispheres.[27]
