The Solar System is the gravitationally bound system of the Sun and the objects that orbit it. It formed 4.6 billion years ago from the gravitational collapse of a giant interstellar molecular cloud. The vast majority (99.86%) of the system's mass is in the Sun, with most of the remaining mass contained in the planet Jupiter. The four inner system planets—Mercury, Venus, Earth and Mars—are terrestrial planets, being composed primarily of rock and metal. The four giant planets of the outer system are substantially larger and more massive than the terrestrials. The two largest, Jupiter and Saturn, are gas giants, being composed mainly of hydrogen and helium; the next two, Uranus and Neptune, are ice giants, being composed mostly of volatile substances with relatively high melting points compared with hydrogen and helium, such as water, ammonia, and methane. All eight planets have nearly circular orbits that lie near the plane of Earth's orbit, called the ecliptic.
The Theogony is a poem by Hesiod describing the origins and genealogies of the Greek gods, composed c. 730–700 BC. It is written in the Epic dialect of Ancient Greek and contains 1022 lines.
A terrestrial planet, telluric planet, or rocky planet, is a planet that is composed primarily of silicate rocks or metals. Within the Solar System, the terrestrial planets accepted by the IAU are the inner planets closest to the Sun, i.e. Mercury, Venus, Earth and Mars. Among astronomers who use the geophysical definition of a planet, two or three planetary-mass satellites – Earth's Moon, Io, and sometimes Europa – may also be considered terrestrial planets; and so may be the rocky protoplanet-asteroids Pallas and Vesta. The terms "terrestrial planet" and "telluric planet" are derived from Latin words for Earth, as these planets are, in terms of structure, Earth-like.
A natural satellite is, in the most common usage, an astronomical body that orbits a planet, dwarf planet, or small Solar System body. Natural satellites are often colloquially referred to as moons, a derivation from the Moon of Earth.
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object.
Rhea or Rheia is a mother goddess in ancient Greek religion and Greek mythology, the Titaness daughter of the earth goddess Gaia and the sky god Uranus, himself a son of Gaia. She is the older sister of Cronus, who was also her consort, and the mother of the five eldest Olympian gods Hestia, Demeter, Hera, Poseidon and Zeus, and the king of the Underworld Hades. But Cronus learnt that he was destined to be overthrown by one of his children like his father was before him, so he swallowed all the children Rhea bore as soon as they were born. When Rhea had her sixth and final child, Zeus, she spirited him away and hid him in Crete, giving Cronus a rock to swallow instead, thus saving her youngest son who would go on to challenge his father's rule and rescue the rest of his siblings.
A protoplanet is a large planetary embryo that originated within a protoplanetary disc and has undergone internal melting to produce a differentiated interior. Protoplanets are thought to form out of kilometer-sized planetesimals that gravitationally perturb each other's orbits and collide, gradually coalescing into the dominant planets.
Zeus is a fictional deity, appearing in American comic books published by Marvel Comics. The character is based on the god Zeus in Greek mythology.
The formation of the Solar System began about 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. Most of the collapsing mass collected in the center, forming the Sun, while the rest flattened into a protoplanetary disk out of which the planets, moons, asteroids, and other small Solar System bodies formed.
The fictional portrayal of the Solar System has often included planets, moons, and other celestial objects which do not actually exist in reality. Some of these objects were, at one time, seriously considered as hypothetical planets which were either thought to have been observed, or were hypothesized to be orbiting the Sun in order to explain certain celestial phenomena. Often such objects continued to be used in literature long after the hypotheses upon which they were based had been abandoned.
The planetary systems of stars other than the Sun and the Solar System are a staple element in many works of the science fiction genre.
The Titans of Myth are mythological deities who appear in the Teen Titans and Wonder Woman comic book series by DC Comics.
There are several real or apparent name conflicts between different Solar System bodies, in spite of efforts to give every named body a distinct name. Most of these conflicts are between asteroids and natural satellites of planets, which are named according to different but partially overlapping schemes. Most satellites are named after people and divinities in Greek and Roman mythology; this is rarely true of asteroids currently, with the exception of centaurs and Jupiter trojans, but formerly many asteroids had mythological names, which consequently came into conflict with the names of natural satellites.
In Greek mythology, Cronus, Cronos, or Kronos was the leader and youngest of the first generation of Titans, the divine descendants of the primordial Gaia and Uranus. He overthrew his father and ruled during the mythological Golden Age, until he was overthrown by his own son Zeus and imprisoned in Tartarus. According to Plato, however, the deities Phorcys, Cronus, and Rhea were the eldest children of Oceanus and Tethys.
In Greek mythology, Gaia, also spelled Gaea, is the personification of the Earth and one of the Greek primordial deities. Gaia is the ancestral mother—sometimes parthenogenic—of all life. She is the mother of Uranus, from whose sexual union she bore the Titans, the Cyclopes, and the Giants; as well as of Pontus, from whose union she bore the primordial sea gods. Her equivalent in the Roman pantheon was Terra.
The familiar name and large size of the Titans have made them dramatic figures suited to market-oriented popular culture.
A subsatellite, also known as a submoon, or moonmoon, is a "moon of a moon" or a hypothetical natural satellite that orbits the moon of a planet.
Comparative planetary science or comparative planetology is a branch of space science and planetary science in which different natural processes and systems are studied by their effects and phenomena on and between multiple bodies. The planetary processes in question include geology, hydrology, atmospheric physics, and interactions such as impact cratering, space weathering, and magnetospheric physics in the solar wind, and possibly biology, via astrobiology.
The following outline is provided as an overview of and topical guide to Saturn:
