Metis (moon)

Metis (/ˈmiːtᵻs/; Greek: Μήτις), also known as Jupiter XVI, is the innermost moon of Jupiter. It was discovered in 1979 in images taken by Voyager 1, and was named in 1983 after the first wife of Zeus, Metis. Additional observations made between early 1996 and September 2003 by the Galileo spacecraft allowed its surface to be imaged.

Metis is tidally locked to Jupiter, and its shape is strongly asymmetrical, with one of the diameters being almost twice as large as the smallest one. It is also one of the two moons known to orbit Jupiter in less than the length of Jupiter's day, the other being Adrastea. It orbits within the main ring of Jupiter, and is thought to be a major contributor of material to the rings.

Discovery and observations

Metis was discovered in 1979 by Stephen P. Synnott in images taken by the Voyager 1 probe and was provisionally designated as S/1979 J 3. In 1983 it was officially named after the mythological Metis, a Titaness who was the first wife of Zeus (the Greek equivalent of Jupiter). The photographs taken by Voyager 1 showed Metis only as a dot, and hence knowledge about Metis was very limited until the arrival of the Galileo spacecraft. Galileo imaged almost all of the surface of Metis and put constraints on its composition by 1998.

9 Metis

9 Metis is one of the larger main-belt asteroids. It is composed of silicates and metallic nickel-iron, and may be the core remnant of a large asteroid that was destroyed by an ancient collision. Metis is estimated to contain just under half a percent of the total mass of the asteroid belt.

Discovery and naming

Metis was discovered by Andrew Graham on 25 April 1848, at Markree Observatory in Ireland; it was his only asteroid discovery. It also has been the only asteroid to have been discovered as a result of observations from Ireland until 7 October 2008, when, 160 years later, Dave McDonald from observatory J65 discovered 2008 TM9. Its name comes from the mythological Metis, a Titaness and Oceanid, daughter of Tethys and Oceanus. The name Thetis was also considered and rejected (it would later devolve to 17 Thetis).

Characteristics

Metis' direction of rotation is unknown at present, due to ambiguous data. Lightcurve analysis indicates that the Metidian pole points towards either ecliptic coordinates (β, λ) = (23°, 181°) or (9°, 359°) with a 10° uncertainty. The equivalent equatorial coordinates are (α, δ) = (12.7 h, 21°) or (23.7 h, 8°). This gives an axial tilt of 72° or 76°, respectively.

Metis (software)

Metis is a family of client and server products for creating, visualizing, changing, sharing and managing visual enterprise models. It was originally created by a Norwegian company named Metis AS, which was bought by Digital Equipment Corporation. Metis was then sold to AT&T. After the AT&T/NCR split in 1996, Metis became a part of NCR. In 2001 the Metis group and product was sold to Computas AS. In 2004 Computas AS was split into two: Computas, and Computas Technology. In 2005 Computas Technology was merged with Troux Technologies, an Austin, Texas-based firm, which now holds the rights to the product.

In addition to providing general modeling mechanisms and primitives, Metis doesn't restrict the modeling to one particular methodology. It provides the opportunity for developing in several modeling languages and comes with built-in templates for UML, BPM, EEML, GEM, I*, MEML-2 and Misuse, together with an option to merge these so that one can benefit from the strongest aspects of each language.

Métis

In Canada, the Métis, as defined by the Constitution Act 1982, are Aboriginal people. They are descendants of specific mixed First Nations and European ancestry who self-identify as Métis, and are accepted into their current community. The Métis people are the modern descendants of Indigenous women in Canada and the colonial-era French, Scottish and English trappers and fur traders they married.

The descendants of these unions formed communities, first around hunting, trapping and fur trading, that to this day have a unique and specific culture. The term "Métis" does not mean any white person who believes they also have some Native ancestry. It refers to specific, intact communities of Aboriginal people and their culture. The majority of Métis people have combined Algonquian and French ancestry.

Etymology

The word "Métis" (from Old French mestis, from Late Latin mixtīcius) was first used to refer to people of mixed race born generally to indigenous women and French men in New France and La Louisiane. Over time in Canada, many mixed-race people married within their own group, maintaining contact with their indigenous culture. The term developed in association with these particular communities of mixed-race people and their unique culture.

Moon

The Moon (in Greek: σελήνη Selene, in Latin: Luna) is Earth's only natural satellite. It is one of the largest natural satellites in the Solar System, and, among planetary satellites, the largest relative to the size of the planet it orbits (its primary). It is the second-densest satellite among those whose densities are known (after Jupiter's satellite Io).

The Moon is thought to have formed approximately 4.5 billion years ago, not long after Earth. There are several hypotheses for its origin; the most widely accepted explanation is that the Moon formed from the debris left over after a giant impact between Earth and a Mars-sized body called Theia.

The Moon is in synchronous rotation with Earth, always showing the same face with its near side marked by dark volcanic maria that fill between the bright ancient crustal highlands and the prominent impact craters. It is the second-brightest regularly visible celestial object in Earth's sky after the Sun, as measured by illuminance on Earth's surface. Although it can appear a very bright white, its surface is actually dark, with a reflectance just slightly higher than that of worn asphalt. Its prominence in the sky and its regular cycle of phases have, since ancient times, made the Moon an important cultural influence on language, calendars, art, and mythology.

Moon (visual novel)

Moon (styled as Moon.) is a Japanese adult visual novel developed by Tactics, a brand of Nexton, released on November 21, 1997 playable on Windows PCs. The game was described by the development team as a "Reaching the Heart AVG" (心に届くAVG, Kokoro ni Todoku AVG). The story follows the protagonist Ikumi Amasawa, a girl who joins an organization called Fargo in the hopes of discovering why and how her mother died, who was a member of the same group. The gameplay in Moon follows a branching plot line which offers pre-determined scenarios with courses of interaction, and focuses on the three female main characters. The game ranked twice in the national top 50 for best-selling PC games sold in Japan.

Much of the staff that created the game later became the founding members of the visual novel brand Key. Moon was the starting point for Key's origins, and was the first time the principal Key team was formed. A novel based on the game written by Midori Tateyama was released in July 1998 by Movic. The game's original soundtrack was released bundled with Dōsei's soundtrack in August 2000 at Comiket 58; Dōsei was Tactics' first game. Moon has been referenced in other media not directly related to the game, such as in Tactics' third game One: Kagayaku Kisetsu e, and in the second anime adaptation of Key's first game Kanon.

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.