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.

USA (disambiguation)

USA or U.S.A. usually refers to the United States of America, a country in North America.

USA or U.S.A. may also refer to:

Places

Business

Universities

Other uses

American Revolution

The American Revolution was a political upheaval that took place between 1765 and 1783 during which colonists in the Thirteen American Colonies rejected the British monarchy and aristocracy, overthrew the authority of Great Britain, and founded the United States of America.

Starting in 1765, members of American colonial society rejected the authority of the British Parliament to tax them without colonial representatives in the government. During the following decade, protests by colonists—known as Patriots—continued to escalate, as in the Boston Tea Party in 1773 during which patriots destroyed a consignment of taxed tea from the Parliament-controlled and favored East India Company. The British responded by imposing punitive laws—the Coercive Acts—on Massachusetts in 1774, following which Patriots in the other colonies rallied behind Massachusetts. In late 1774 the Patriots set up their own alternative government to better coordinate their resistance efforts against Great Britain, while other colonists, known as Loyalists, preferred to remain aligned to the British Crown.

USA-229

USA-229, known before launch as NRO Launch 34 (NROL-34), is a pair of American signals intelligence satellites which were launched in 2011. They are operated by the United States National Reconnaissance Office.

Both satellites were deployed by a United Launch Alliance Atlas V 411 carrier rocket, which launched from Space Launch Complex 3E at the Vandenberg Air Force Base. The launch occurred at 04:24 UTC on 15 April 2011. The rocket placed the satellites into a low Earth orbit. By 04:29 UTC, official updates on the status of the spacecraft had been discontinued.

Whilst details of the satellites and their missions are officially classified, amateur observers have identified that the Atlas V deployed two satellites, one of which has officially been catalogued as debris. The two spacecraft have been identified as being a pair of third or fourth generation Naval Ocean Surveillance System satellites. Amateur observations have located the spacecraft in an orbit with a perigee of 1,025 kilometres (637 mi) and an apogee of 1,207 kilometres (750 mi), inclined at 64.4 degrees to the plane of the equator. Current generation NOSS satellites are always launched and operated in pairs, and are used to locate and track ships from the radio transmissions that they emit.