After the discovery of Pluto and Charon, no more trans-Neptunian objects (TNOs) were found until 15760 Albion in 1992. [56] Since then, thousands of such objects have been discovered. Most are now recognized as part of the Kuiper belt, a swarm of icy bodies left over from the Solar System's formation that orbit near the ecliptic plane just beyond Neptune. Though none were as large as Pluto, some of these distant trans-Neptunian objects, such as Sedna, were initially described in the media as "new planets". [57] Venkatesh Ketakar" redirects here. For the sociologist, see Shridhar Venkatesh Ketkar. Percival Lowell, originator of the Planet X hypothesis Even without gravitational evidence, Mike Brown, the discoverer of Sedna, has argued that Sedna's 12,000-year orbit means that probability alone suggests that an Earth-sized object exists beyond Neptune. Sedna's orbit is so eccentric that it spends only a small fraction of its orbital period near the Sun, where it can be easily observed. This means that unless its discovery was a freak accident, there is probably a substantial population of objects roughly Sedna's diameter yet to be observed in its orbital region. [77] Mike Brown noted that In January 2016, Konstantin Batygin and Michael E. Brown published their “Planet Nine” hypothesis. Using a computer model, they showed that a distant planet could explain the unique orbits of observable objects in the solar system. In The Search for Planet X, 1-4 players take on the role of astronomers, surveying the night sky and attempting to deduce the location of this hidden planet.

The app also offers the useful option of providing players with different amounts of starting info, allowing for the option of a handicap system if some players are more experienced than others. But experience can come with another peril than just game balance: despite the fact each game will have a fresh setup to solve, doing so feels much the same every time. With limited ways to glean information, replayability is dependent on enjoying solving variants of that same puzzle. Chang, Kenneth (20 January 2016). "Ninth Planet May Exist Beyond Pluto, Scientists Report". The New York Times . Retrieved 22 January 2016. Each of the two new studies found objects the other one missed, suggesting that even more distant neighbors exist outside the solar system. Using public data on the orbits of the extreme trans-Neptunian objects, it has been confirmed that a statistically significant (62σ) asymmetry between the shortest mutual ascending and descending nodal distances does exist; in addition, multiple highly improbably (p < 0.0002) correlated pairs of orbits with mutual nodal distances as low as 0.2AU at 152AU from the Solar System's barycentre or 1.3AU at 339AU have been found. [103] Both findings suggest that massive perturbers may exist at hundreds of AUs from the Sun and are difficult to explain within the context of a uniform distribution of orbital orientations in the outermost Solar System. [104] 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. [3] 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 (IAU) reclassified Pluto and its largest neighbours as dwarf planets, leaving Neptune the farthest known planet in the Solar System. [4]Thomas O'Toole (1983-12-30). "Mystery Heavenly Body Discovered". The Washington Post. p.A1. Archived from the original on 2008-02-01 . Retrieved 2008-01-28. a b Schilling, Govert (11 January 2008). "The mystery of PlanetX". New Scientist. pp.30–33 . Retrieved 25 June 2008.

Asteroids (4) – These will always appear in pairs, which means they can be in two groups of 2 or one group of 4. a b Brown, Mike (11 April 2007). "Pluto and the outer solar system". Lowell Lectures in Astronomy. Boston, MA: Museum of Science, Boston / WGBH. Archived from the original on 2008-01-03 . Retrieved 2008-07-13. a b c JG Chhabra; SD Sharma; M Khanna (1984). "Prediction of Pluto by V. P. Ketakar" (PDF). Indian Journal of History of Science. 19 (1): 18–26. Bibcode: 1984InJHS..19...18C. Archived from the original (PDF) on 2009-02-25 . Retrieved 2008-09-04. Brady, Joseph L. (1972). "The Effect of a Trans-Plutonian Planet on Halley's Comet". Publications of the Astronomical Society of the Pacific. 84 (498): 314–322. Bibcode: 1972PASP...84..314B. doi: 10.1086/129290. S2CID 122053270.de la Fuente Marcos, C.; de la Fuente Marcos, R. (1 September 2014). "Extreme trans-Neptunian objects and the Kozai mechanism: signalling the presence of trans-Plutonian planets". Monthly Notices of the Royal Astronomical Society: Letters. 443 (1): L59–L63. arXiv: 1406.0715. Bibcode: 2014MNRAS.443L..59D. doi: 10.1093/mnrasl/slu084. S2CID 118622180. Note: The above values represent a Standard Mode game. When playing in Expert Mode, there will be 5 Truly Empty Sectors and 4 Dwarf Planets. These Dwarf Planets always appear in one of 6 possible patterns, which are shown on your player screen. The app will ask which side of the board you’re facing and give you some starting information (with more experienced players being given less). The Laws Of Logic Truly Empty Sectors (2) – These sectors have nothing in, which can be useful for helping deduce where other objects are. Submit a Theory – if you are 1/2/3 spaces behind, you can submit one theory. If you are 4/5 spaces behind, you can submit two.

A news release from the Harvard Center for Astrophysics expands, "Popular theory associates the formation of the Oort cloud with debris left over from the formation of the solar system and its neighbors, where objects were scattered by the planets to great distances and some were exchanged amongst stars. But a binary model could be the missing piece in the puzzle.I’d also hate to be the person who sits down to play but isn’t used to any kind of logic problem. Maybe they’ve never done a logic grid, a sudoku puzzle, or a nonogram. The kind of thinking that helps you solve puzzles like these is normally learned, rather than innate, which makes The Search for Planet X a game where you need to be careful who your audience is. Bear that in mind when you’re deciding whether to buy the game or not. Final thoughts A. Brunini & M.D. Melita (2002). "The existence of a planet beyond 50 AU and the Orbital Distribution of the Classical Edgeworth–Kuiper-Belt Objects". Icarus. 160 (1): 32–43. Bibcode: 2002Icar..160...32B. doi: 10.1006/icar.2002.6935. hdl: 11336/37037.