Bond , G. Bond  and William Lassell. The use of long-exposure photographic plates made possible the discovery of additional moons. The first to be discovered in this manner, Phoebe , was found in by W. A few years later it was realized that all observations of could only be explained if another satellite had been present and that it had an orbit similar to that of Janus. It shares the same orbit with Janus—the only known example of co-orbitals in the Solar System.
The study of the outer planets has since been revolutionized by the use of unmanned space probes. The arrival of the Voyager spacecraft at Saturn in — resulted in the discovery of three additional moons — Atlas , Prometheus and Pandora , bringing the total to In , Pan was discovered in archival Voyager images. The Cassini mission,  which arrived at Saturn in the summer of , initially discovered three small inner moons including Methone and Pallene between Mimas and Enceladus as well as the second trojan moon of Dione — Polydeuces.
It also observed three suspected but unconfirmed moons in the F Ring. Study of Saturn's moons has also been aided by advances in telescope instrumentation, primarily the introduction of digital charge-coupled devices which replaced photographic plates. For the entire 20th century, Phoebe stood alone among Saturn's known moons with its highly irregular orbit.
Beginning in , however, three dozen additional irregular moons have been discovered using ground-based telescopes. Some of the 82 known satellites of Saturn are considered lost because they have not been observed since their discovery and hence their orbits are not known well enough to pinpoint their current locations. The modern names for Saturnian moons were suggested by John Herschel in Some asteroids share the same names as moons of Saturn: 55 Pandora , Dione , Rhea , Prometheus , Epimetheus , and Pan.
In addition, two more asteroids previously shared the names of Saturnian moons until spelling differences were made permanent by the International Astronomical Union IAU : Calypso and asteroid 53 Kalypso ; and Helene and asteroid Helena. Although the boundaries may be somewhat vague, Saturn's moons can be divided into ten groups according to their orbital characteristics. Many of them, such as Pan and Daphnis , orbit within Saturn's ring system and have orbital periods only slightly longer than the planet's rotation period.
The moons of the Norse group also orbit in the opposite direction to Saturn's rotation. Unlike the A Ring moonlets see below , it does not induce a 'propeller' feature, probably due to the density of the B Ring. In , four tiny moonlets were found in Cassini images of the A Ring. These are large enough to clear continuous gaps in the ring.
The moonlets were probably formed from the breakup of a larger satellite. Similar moonlets may reside in the F Ring. One of the recently discovered moons, Aegaeon , resides within the bright arc of G Ring and is trapped in the mean-motion resonance with Mimas.
The moon is the largest among the population of bodies that are sources of dust in this ring. Shepherd satellites are small moons that orbit within, or just beyond, a planet's ring system. They have the effect of sculpting the rings: giving them sharp edges, and creating gaps between them. The cores with sizes from one-third to one-half the present-day moons may be themselves collisional shards formed when a parental satellite of the rings disintegrated.
Janus and Epimetheus are called co-orbital moons. Instead of colliding, however, their gravitational interaction causes them to swap orbits every four years. The innermost large moons of Saturn orbit within its tenuous E Ring , along with three smaller moons of the Alkyonides group.
Named after the Alkyonides of Greek mythology, they are some of the smallest moons in the Saturn system. Anthe and Methone have very faint ring arcs along their orbits, whereas Pallene has a faint complete ring. Trojan moons are a unique feature only known from the Saturnian system. A trojan body orbits at either the leading L 4 or trailing L 5 Lagrange point of a much larger object, such as a large moon or planet.
Tethys has two trojan moons, Telesto leading and Calypso trailing , and Dione also has two, Helene leading and Polydeuces trailing. Irregular moons are small satellites with large-radii, inclined, and frequently retrograde orbits, believed to have been acquired by the parent planet through a capture process.
They often occur as collisional families or groups. It appears to be released by sunlight or energetic particles hitting the moon and breaking down the water ice on the surface. Hyperion may not be one of Saturn's major moons, but it certainly has an appearance that's out of this world.
The moon is highly porous and has a very low density. It's thought that any impacts simply compress the moon, just like sticking your thumb into a sponge to mould the surface. This article was originally published on The Conversation. Read the original article. More from Astronomy and Astrophysics.
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The surface of Iapetus shows a striking difference in reflectivity between its leading and trailing hemispheres. The leading hemisphere is remarkably dark, the darkest material concentrated at the apex of orbital motion. Cassini spectral data show the presence of carbon dioxide, organics, and cyanide compounds. The trailing hemisphere, which is as much as 10 times more reflective than the leading one, is heavily cratered and is mostly water ice.
The reflectivity difference is caused by dark material from the Phoebe dust ring collecting on the leading hemisphere of Iapetus and absorbing more sunlight, which heats up this region. Any water ice there turns to water vapour, which condenses onto the trailing hemisphere and freezes. The low mean density of Iapetus suggests that the moon as a whole is mostly water ice.
Saturn's newfound moons are believed to have arisen after the formation of the planets billions of years ago was mostly complete. Each has a diameter of about 5 kilometers, or 3 miles. Although so what, it was nonetheless of great benefit!
It is the second largest moon of Saturn measuring 1, km across and is the 9th largest natural satellite in the solar system Iapetus — With a diameter of 1, km, it is the 3rd largest moon of Saturn. Moons of Saturn Emma Nation. This is great for my project i have to do on saturn and its moons. Thanks for all the info. Steve Edmonds. Banana Bob. Getting Pregnant after Miscarriage.Saturn has 82 moons. Fifty-three moons are confirmed and named and another 29 moons are awaiting confirmation of discovery and official naming. Saturn's moons range in size from larger than the planet Mercury — the giant moon Titan — to as small as a sports arena. The moons shape, contribute and also collect material from Saturn's rings and.