Satellite

In the context of spaceflight, a satellite is an artificial object which has been intentionally placed into orbit. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as Earth's Moon.

The world's first artificial satellite, the Sputnik 1, was launched by the Soviet Union in 1957. Since then, thousands of satellites have been launched into orbit around the Earth. Some satellites, notably space stations, have been launched in parts and assembled in orbit. Artificial satellites originate from more than 40 countries and have used the satellite launching capabilities of ten nations. About a thousand satellites are currently operational, whereas thousands of unused satellites and satellite fragments orbit the Earth as space debris. A few space probes have been placed into orbit around other bodies and become artificial satellites to the Moon, Mercury, Venus, Mars, Jupiter, Saturn, Vesta, Eros, Ceres, and the Sun.

Satellites are used for a large number of purposes. Common types include military and civilian Earth observation satellites, communications satellites, navigation satellites, weather satellites, and research satellites. Space stations and human spacecraft in orbit are also satellites. Satellite orbits vary greatly, depending on the purpose of the satellite, and are classified in a number of ways. Well-known (overlapping) classes include low Earth orbit, polar orbit, and geostationary orbit.

Satellite (moth)

The Satellite (Eupsilia transversa) is a moth of the family Noctuidae. It is distributed throughout the Palearctic.

This is a fairly variable species with greyish or reddish brown forewings, often marked with darker bands. The common name derives from the prominent stigma, ranging in colour from white or yellow to red, which has two smaller spots close to it, apparently “in orbit”. The hindwings are brown with a paler fringe. The wingspan is 40–48 mm. This species flies at night from September to April and is active on mild nights throughout the winter. It will come to light but is more strongly attracted to sugar and various flowers.

Distribution

The species ranges from Ireland to Japan. Specifically, south to Northern Spain, Sardinia, Central Italy then Macedonia, Bulgaria, Asia minor and the Caucasus East to Central Asia and the Russian Far East and Siberia before reaching Japan. In the North, the geographical presence extends to Scotland and the Orkney Islands. Individuals are reported by Iceland. In Fennoscandia the range extends almost to the Arctic Circle, as well as in northern Russia. The species is very cold tolerant and lives in a variety of habitats, from forests to open grasslands, from the lowlands up to above the tree line. From temperate areas to the subarctic tundra. The species rises up to 1800 m in the Alps.

Natural satellite

A natural satellite is a celestial body that orbits another celestial body of greater mass (e.g., a planet, star, or dwarf planet), which is called its primary. For example, the Moon is a natural satellite of Earth, and Earth is a natural satellite of the Sun.

In the Solar System there are 173 known natural satellites which orbit within 6 planetary satellite systems. In addition, several other objects are known to have satellites, including three IAU-listed dwarf planets: Pluto, Haumea, and Eris.As of January 2012, over 200 minor-planet moons have been discovered. There are 76 known objects in the asteroid belt with satellites (five with two each), four Jupiter trojans, 39 near-Earth objects (two with two satellites each), and 14 Mars-crossers. There are also 84 known natural satellites of trans-Neptunian objects. Some 150 additional small bodies have been observed within the rings of Saturn, but only a few were tracked long enough to establish orbits. Planets around other stars are likely to have satellites as well, and although numerous candidates have been detected to date, none have yet been confirmed.

List of Rome characters

This list is intended as a guide to most characters for the HBO series Rome. More details can be found on the individual character articles linked within the tables, as well as the article Minor characters of Rome.

The historical figures upon which certain characters are based are noted where appropriate.

Additionally, episode-specific and very minor characters may be listed in each episode's article page.

Primary characters

Secondary characters

Minor

Noble characters

Gaia (mythology)

In Greek mythology, Gaia, (GAY-ə or GAH-yə; from Ancient Greek Γαῖα, a poetical form of Γῆ Gē, Ge, "land" or "earth";) also spelled Gaea, was the personification of the Earth and one of the Greek primordial deities. Gaia was the great mother of all: the primal Greek Mother Goddess; creator and giver of birth to the Earth and all the Universe; the heavenly gods, the Titans, and the Giants were born to her. The gods reigning over their classical pantheon were born from her union with Uranus (the sky), while the sea-gods were born from her union with Pontus (the sea). Her equivalent in the Roman pantheon was Terra.

Etymology

The Greek word γαῖα (transliterated as gaia) is a collateral form of γῆ (gē, Doric γᾶ ga and probably δᾶ da) meaning Earth, a word of uncertain origin.R. S. P. Beekes has suggested a Pre-Greek origin. It, however, could be related to the Avestan word gaiia 'life;' cf. Av. gaēθā '(material) world, totality of creatures' and gaēθiia 'belonging to/residing in the worldly/material sphere, material'; and probably even Av, gairi 'mountain'.

List of Foundation universe planets

This is a list of Foundation universe planets featured or mentioned in the Robot series, Empire series, and Foundation series created by Isaac Asimov.

61 Cygni

The star system 61 Cygni, in the Sirius Sector, is advanced by Lord Dorwin as the potential site for a planet of origin for the human species. Lord Dorwin cites 'Sol' (meaning Earth's Sun) and three other planetary systems in the Sirius Sector, along with Arcturus in the Arcturus Sector, as potential original worlds. (This fact seems to be contradicted by information given in Foundation and Earth). Claims were made as early as 1942 that 61 Cygni had a planetary system, though to date, none has been verified, and Asimov was aware of these claims.

Alpha

Alpha is a fictional planet orbiting the larger of the two stars in the Alpha Centauri system.

In Asimov's Foundation Series, Alpha Centauri is cited by Lord Dorwin as one of the solar systems where humankind potentially originated. The others are Sol, Sirius, 61 Cygni and Arcturus. Beyond mentioning that it is in the Sirius Sector, Dorwin gives no further details.