Planets beyond Neptune

Following the discovery of the planet Neptune in 1846, there was considerable speculation that another planet might exist beyond its orbit. The search began in the mid-19th century and culminated at the start of the 20th with Percival Lowell's quest for Planet X. Lowell proposed the Planet X hypothesis to explain apparent discrepancies in the orbits of the giant planets, particularly Uranus and Neptune, speculating that the gravity of a large unseen ninth planet could have perturbed Uranus enough to account for the irregularities.

Clyde Tombaugh's discovery of Pluto in 1930 appeared to validate Lowell's hypothesis, and Pluto was officially named the ninth planet. In 1978, Pluto was conclusively determined to be too small for its gravity to affect the giant planets, resulting in a brief search for a tenth planet. The search was largely abandoned in the early 1990s, when a study of measurements made by the Voyager 2 spacecraft found that the irregularities observed in Uranus's orbit were due to a slight overestimation of Neptune's mass. After 1992, the discovery of numerous small icy objects with similar or even wider orbits than Pluto led to a debate over whether Pluto should remain a planet, or whether it and its neighbours should, like the asteroids, be given their own separate classification. Although a number of the larger members of this group were initially described as planets, in 2006 the International Astronomical Union reclassified Pluto and its largest neighbours as dwarf planets, leaving Neptune the farthest known planet in the Solar System.

Planet X (disambiguation)

Planet X is a term used to describe hypothesized planets, orbiting the Sun beyond Neptune (the 8th planet).

Planet X also may refer to:

Science fiction

Music

Other uses

GameStop

GameStop Corporation, simply referred to as GameStop, is an American video game, consumer electronics, and wireless services retailer. The company is headquartered in Grapevine, Texas, United States, and operates 6,457 retail stores throughout the United States, Canada, Australia, New Zealand, and Europe. The company's retail stores primarily operate under the GameStop, EB Games, and Micromania brands.

In addition to retail stores, GameStop also owns Kongregate, a site for browser-based video games; and Game Informer, a video game magazine; Simply Mac, an Apple products reseller; and Spring Mobile, an AT&T wireless reseller. It also operates Cricket Wireless branded retail stores as an authorized agent. Cricket is an AT&T brand pre-paid wireless retailer.J. Paul Raines is GameStop's chief executive officer.

Operations

GameStop is divided into two operating segments: Video Game Brands and Technology Brands. The Technology Brands was created during the fourth quarter of 2013, and houses the companies Simply Mac, Spring Mobile, and Aio Wireless business. As of April 2014, the Technology Brands segment included 218 retail outlets. GameStop's Video Game Brands includes the company's other businesses such as video game and consumer electronics retail shops; Kongregate, a digital video game distribution site; and buymytronics.com, a consumer electronics marketplace. Pre-owned and value video games accounted for 47% of GameStop's gross revenue for the fiscal year ending February 2014.