The scattered disc is a distant region of the Solar System that is sparsely populated by icy minor planets, a subset of the broader family of trans-Neptunian objects. The scattered disc objects have orbital eccentricities ranging as high as 0.8, inclinations as high as 40° and perihelia greater than 30 astronomical units. These extreme orbits are believed to be the result of gravitational "scattering" by the gas giants,

and the objects continue to be subject to perturbation by the planet Neptune. While the nearest distance to the Sun approached by scattered objects is about 30–35 AU, their orbits can extend well beyond 100 AU. This makes scattered objects "among the most distant and cold objects in the Solar System". The innermost portion of the scattered disc overlaps with a torus-shaped region of orbiting objects known as the Kuiper belt, but its outer limits reach much farther away from the Sun and farther above and below the ecliptic than the belt proper. Due to its unstable nature, astronomers now consider the scattered disc to be the place of origin for most periodic comets observed in the Solar System, with the centaurs, a population of icy bodies between Jupiter and Neptune, being the intermediate stage in an object's migration from the disc to the inner Solar System. Eventually, perturbations from the giant planets send such objects towards the Sun, transforming them into periodic comets. Many Oort cloud objects are also believed to have originated in the scattered disc.

Read the rest of this article: http://en.wikipedia.org/wiki/Scattered_disc

_______________________________ Today's selected anniversaries:

425:

Valentinian III became Emperor of the Western Roman Empire at the age of six. http://en.wikipedia.org/wiki/Valentinian_III

1642:

The Battle of Edgehill, the first pitched battle of the First English Civil War between the Royalists and the Parliamentarians, was fought to an inconclusive result near Edge Hill and Kineton in southern Warwickshire. http://en.wikipedia.org/wiki/Battle_of_Edgehill

1739:

Great Britain declared war on Spain, starting the War of Jenkins' Ear. http://en.wikipedia.org/wiki/War_of_Jenkins%27_Ear

1955:

Prime Minister Ngo Dinh Diem defeated Emperor Bao Dai in a fraudulent referendum supervised by his brother Ngo Dinh Nhu on the future of the monarchy in South Vietnam. http://en.wikipedia.org/wiki/1955_State_of_Vietnam_referendum

1956:

The Hungarian Revolution began as a peaceful student demonstration which attracted thousands as it marched through central Budapest to the Parliament building. http://en.wikipedia.org/wiki/Hungarian_Revolution_of_1956

1983:

Lebanese Civil War: Suicide bombers destroyed two barracks in Beirut, Lebanon, killing 241 U.S. servicemen and 58 French paratroopers of the international peacekeeping force. http://en.wikipedia.org/wiki/1983_Beirut_barracks_bombing

_____________________________ Wiktionary's word of the day:

haiku (n): 1. A Japanese poem of a specific form, consisting of three lines, the first and last consisting of five morae, and the second consisting of seven morae, usually with an emphasis on the season or a naturalistic theme. 2. A three-line poem in any language, with five syllables in the first and last lines and seven syllables in the second, usually with an emphasis on the season or a naturalistic theme http://en.wiktionary.org/wiki/haiku

___________________________ Wikiquote quote of the day:

We ought to hate very rarely, as it is too fatiguing; remain indifferent to a great deal, forgive often and never forget. --Sarah Bernhardt http://en.wikiquote.org/wiki/Sarah_Bernhardt