A planet is a large, rounded astronomical body that is generally required to be in orbit around a star, stellar remnant, or brown dwarf, and is not one itself. The Solar System has eight planets by the most restrictive definition of the term: the terrestrial planets Mercury, Venus, Earth, and Mars, and the giant planets Jupiter, Saturn, Uranus, and Neptune. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a young protostar orbited by a protoplanetary disk. Planets grow in this disk by the gradual accumulation of material driven by gravity, a process called accretion.
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. It is one of the most important sources for the understanding of early Greek cosmology.
In Greek mythology, the Titans were the pre-Olympian gods. According to the Theogony of Hesiod, they were the twelve children of the primordial parents Uranus (Sky) and Gaia (Earth), with six male Titans—Oceanus, Coeus, Crius, Hyperion, Iapetus, and Cronus—and six female Titans, called the Titanides or Titanesses—Theia, Rhea, Themis, Mnemosyne, Phoebe, and Tethys.
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: 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. The large rocky asteroids Pallas and Vesta are sometimes included as well, albeit rarely. The terms "terrestrial planet" and "telluric planet" are derived from Latin words for Earth, as these planets are, in terms of structure, Earth-like. Terrestrial planets are generally studied by geologists, astronomers, and geophysicists.
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 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 mythology, the Titan 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 and Hades, king of the underworld.
A planetary system is a set of gravitationally bound non-stellar bodies in or out of orbit around a star or star system. Generally speaking, systems with one or more planets constitute a planetary system, although such systems may also consist of bodies such as dwarf planets, asteroids, natural satellites, meteoroids, comets, planetesimals and circumstellar disks. For example, the Sun together with the planetary system revolving around it, including Earth, form the Solar System. The term exoplanetary system is sometimes used in reference to other planetary systems.
There is evidence that 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 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 Ancient Greek religion and 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 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 Earth. Gaia is the ancestral mother—sometimes parthenogenic—of all life. She is the mother of Uranus (Sky), from whose sexual union she bore the Titans, the Cyclopes, and the Giants, as well as of Pontus (Sea), from whose union she bore the primordial sea gods. Her equivalent in the Roman pantheon was Terra.
Universe Sandbox is a series of interactive space sandbox gravity simulator educational software video games. Using Universe Sandbox, users can see the effects of gravity on objects in the universe and run scale simulations of the Solar System, various galaxies or other simulations, while at the same time interacting and maintaining control over gravity, time, and other objects in the universe, such as moons, planets, asteroids, comets, and black holes. The original Universe Sandbox was only available for Windows-based PCs, but an updated version was released for Windows, macOS, and Linux in 2015.
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 informally a moonmoon, is a "moon of a moon" or a hypothetical natural satellite that orbits the moon of a planet.
The following outline is provided as an overview of and topical guide to the Solar System:
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:
