Joined in 2023 
82 
63 About this deal
de la Fuente Marcos, C.; de la Fuente Marcos, R. (18 February 2021). "Memories of past close encounters in extreme trans-Neptunian space: Finding unseen planets using pure random searches". Astronomy and Astrophysics Letters. 646: L14 (9 pp). arXiv: 2102.02220. Bibcode: 2021A&A...646L..14D. doi: 10.1051/0004-6361/202140311. S2CID 231802033. Millholland, Sarah; Laughlin, Gregory (2017). "Constraints on Planet Nine's Orbit and Sky Position within a Framework of Mean Motion Resonances". The Astronomical Journal. 153 (3): 91. arXiv: 1612.07774. Bibcode: 2017AJ....153...91M. doi: 10.3847/1538-3881/153/3/91. S2CID 119325788. 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] 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 continued at the start of the 20th with Percival Lowell's quest for Planet X. Lowell proposed the PlanetX hypothesis to explain apparent discrepancies in the orbits of the giant planets, particularly Uranus and Neptune, [1] speculating that the gravity of a large unseen ninth planet could have perturbed Uranus enough to account for the irregularities. [2]
Lowell's sudden death in 1916 temporarily halted the search for PlanetX. Failing to find the planet, according to one friend, "virtually killed him". [25] Lowell's widow, Constance, engaged in a legal battle with the observatory over Lowell's legacy which halted the search for PlanetX for several years. [26] In 1925, the observatory obtained glass discs for a new 13in (33cm) wide-field telescope to continue the search, constructed with funds from Abbott Lawrence Lowell, [27] Percival's brother. [18] In 1929 the observatory's director, Vesto Melvin Slipher, summarily handed the job of locating the planet to Clyde Tombaugh, a 22-year-old Kansas farm boy who had only just arrived at the Lowell Observatory after Slipher had been impressed by a sample of his astronomical drawings. [26] After 1978, a number of astronomers kept up the search for Lowell's PlanetX, convinced that, because Pluto was no longer a viable candidate, an unseen tenth planet must have been perturbing the outer planets. [44]Central Bureau for Astronomical Telegrams, International Astronomical Union (2006). "Circular No. 8747" (PDF). Archived from the original on February 5, 2007 . Retrieved 2011-07-05.
While the astronomical community widely agrees that PlanetX, as originally envisioned, does not exist, the concept of an as-yet-unobserved planet has been revived by a number of astronomers to explain other anomalies observed in the outer Solar System. [5] As of March 2014, observations with the WISE telescope have ruled out the possibility of a Saturn-sized object (95 Earth masses) out to 10,000 AU, and a Jupiter-sized (≈318 Earth masses) or larger object out to 26,000 AU. [6] Luhman's study found 762 new objects among the data, but no signs of a Saturn-sized object out to 10,000 times the Earth-sun distance (an astronomical unit, or AU; 1 AU is about 93 million miles, or 150 million kilometers). Nor did Luhman spot any Jupiter-size or larger objects out to 26,000 AUs. Clyde W. Tombaugh (1946). "The Search for the Ninth Planet, Pluto". Astronomical Society of the Pacific Leaflets. 5 (209): 73–80. Bibcode: 1946ASPL....5...73T. Patryk S., Lykawka; Tadashi, Mukai (2008). "An Outer Planet Beyond Pluto and the Origin of the Trans-Neptunian Belt Architecture". The Astronomical Journal. 135 (4): 1161–1200. arXiv: 0712.2198. Bibcode: 2008AJ....135.1161L. doi: 10.1088/0004-6256/135/4/1161. S2CID 118414447. Myles Standish (1992-07-16). "Planet X– No dynamical evidence in the optical observations". Astronomical Journal. 105 (5): 200–2006. Bibcode: 1993AJ....105.2000S. doi: 10.1086/116575.In 1984, paleontologists claimed that a dim companion star to the sun would explain the periodic occurrence of mass extinctions on Earth. A massive body could theoretically disturb objects in the Oort Cloud surrounding the solar system, sending comets hurtling toward Earth with a deadly frequency. Known as Nemesis, scientists suggested the star could be a red dwarf, or a brown dwarf too dim to observe. Starting in 2018, several surveys have discovered multiple objects located beyond the Kuiper Cliff. Some of these new discoveries are close to the heliopause (120 AU) or well beyond it ( 2018 VG 18, 2018 AG 37, 2020 BE 102, 2020 MK 53). An analysis of the TNO data available prior to September 2023 shows that there is a gap at about 72 AU, far from any mean-motion resonances with Neptune. [88] Such a gap may have been induced by a massive perturber located further away. The game’s attachment to the real subject continues into its components, with player markers provided as charming plastic minis of real-life observatories, and the player screens used to hide your notes and deductions depicting those observatories as well as a couple of data points about them. Unfortunately, the components also relate to the first minor mark against the game – which is that there’s fairly few of them for the RRP of the game. While the cost obviously covers the app as well, it makes The Search for Planet X a little harder to recommend. The existence of Planet 9 was dealt a blow last year, when a team led by physicist Kevin Napier, at the University of Michigan in Ann Arbor, conducted a meta-analysis of surveys examining the orbits of ‘extreme’ trans-Neptunian objects. The researchers found that the objects’ perturbed orbits could actually be explained without the presence of a nearby planet.
Some may therefore feel that after finding Planet X once or twice, they don’t need to keep looking. For players with a penchant for puzzle-solving, though, it’ll be a delight to immediately misplace it and begin searching again.
Contributors
a b "IAU 2006 General Assembly: Resolutions 5 and 6" (PDF). International Astronomical Union. 2006-08-24. That theme is of the real-world research into the hypothesised but as-yet undetected Planet X on the edge of our solar system, presented as a competitive race between players. You’ll be discovering this potential planet (which is guaranteed to exist in the game, if not reality) using an app which provides the results of your investigations and your own logical deductions. Eris was never officially classified as a planet, and the 2006 definition of planet defined both Eris and Pluto not as planets but as dwarf planets because they have not cleared their neighbourhoods. [4] They do not orbit the Sun alone, but as part of a population of similarly sized objects. Pluto itself is now recognized as being a member of the Kuiper belt and the largest dwarf planet, larger than the more massive Eris. As I mentioned, there is a handicap system. You start the game by setting each player’s starting level and the app gives players a different number of clues according to the handicap. To help solve the puzzle you are told how many of each item there are in the solar system and have standard rules about the positioning of each item.
Great Deal 
New Comment