Saturn

Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius about nine times that of Earth. Although only one-eighth the average density of Earth, with its larger volume Saturn is just over 95 times more massive. Saturn is named after the Roman god of agriculture; its astronomical symbol (♄) represents the god's sickle.

Saturn's interior is probably composed of a core of iron–nickel and rock (silicon and oxygen compounds). This core is surrounded by a deep layer of metallic hydrogen, an intermediate layer of liquid hydrogen and liquid helium, and finally outside the Frenkel line a gaseous outer layer. Saturn has a pale yellow hue due to ammonia crystals in its upper atmosphere. Electrical current within the metallic hydrogen layer is thought to give rise to Saturn's planetary magnetic field, which is weaker than Earth's, but has a magnetic moment 580 times that of Earth due to Saturn's larger size. Saturn's magnetic field strength is around one-twentieth of Jupiter's. The outer atmosphere is generally bland and lacking in contrast, although long-lived features can appear. Wind speeds on Saturn can reach 1,800 km/h (500 m/s), higher than on Jupiter, but not as high as those on Neptune.

Grand Tour (novel series)

The Grand Tour is a series of novels written by science fiction author Ben Bova.

The novels present a theme of exploration and colonization of the solar system by humans in the late 21st century. Most of the books focus on the exploration of one particular planet or planetary moon.

Several recurring themes are presented throughout the series. In particular, most of the solar system bodies whose exploration is the focus of a particular novel are presented as having life, either past or present. Many of the expeditions which explore the planets run into serious difficulty. The protagonists of most of these books are presented as initially weak and/or lacking in ability or confidence, and as part of surviving the trials of the story become heroic.

The future humanity as depicted in the Grand Tour novel series is divided between Greens (environmentalists) and wealthy industrialists, as well as between secularists/scientists and religious fundamentalists. These conflicts generally are presented as part of the background and often set up the initial conflicts of each of the books. In addition, several of the books reference, or indeed directly deal with, conflicts between wealthy industrialists and small, independent operators seeking to exploit the solar system's vast untapped mineral wealth.

Planets in astrology

Planets in astrology have a meaning different from the modern astronomical understanding of what a planet is. Before the age of telescopes, the night sky was thought to consist of two very similar components: fixed stars, which remained motionless in relation to each other, and "wandering stars" (Ancient Greek: ἀστέρες πλανῆται asteres planetai), which moved relative to the fixed stars over the course of the year.

To the Greeks and the other earliest astronomers, this group comprised the five planets visible to the naked eye, and excluded the Earth. Although strictly the term "planet" applied only to those five objects, the term was latterly broadened, particularly in the Middle Ages, to include the Sun and the Moon (sometimes referred to as "Lights"), making a total of seven planets. Astrologers retain this definition today.

To ancient astrologers, the planets represented the will of the gods and their direct influence upon human affairs. To modern astrologers the planets represent basic drives or urges in the unconscious, or energy flow regulators representing dimensions of experience. They express themselves with different qualities in the twelve signs of the zodiac and in the twelve houses. The planets are also related to each other in the form of aspects.