{"id":25073,"date":"2021-02-24T18:34:20","date_gmt":"2021-02-24T10:34:20","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/searching-for-planet-9-and-where-new-research-fits-into-the-overall-existence-of-a-theoretical-super-earth-beyond-neptune\/"},"modified":"2021-02-24T18:34:20","modified_gmt":"2021-02-24T10:34:20","slug":"searching-for-planet-9-and-where-new-research-fits-into-the-overall-existence-of-a-theoretical-super-earth-beyond-neptune","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/searching-for-planet-9-and-where-new-research-fits-into-the-overall-existence-of-a-theoretical-super-earth-beyond-neptune\/","title":{"rendered":"Searching for Planet 9 and where new research fits into the overall existence of a theoretical super-Earth beyond Neptune"},"content":{"rendered":"

In large part, it is impossible to have escaped notice of a rather large debate swirling in the planetary community around a theorized super-Earth planet in the outer reaches of our solar system, the existence of which could be one possible explanation to several oddities observed in a very dynamic part of our galactic home. <\/p>\n

So where does current research, distant solar system observations, and searches for the theoretical super-Earth, known both as Planet 9 or Planet X, reside?<\/p>\n<\/p>\n

To start, a brief history.  The first proposals regarding the current Planet 9 candidate stemmed from a prolonged series of observations of extreme trans-Neptunian objects, or eTNOs.  These are small rocky objects whose orbits are well beyond that of Neptune\u2019s and have a semi-major axis (average orbital distance) of 150-250 AU (Astronomical Units, with 1 AU equaling approximately 149,000,000 km or the average distance from the Earth to the Sun).<\/p>\n

The objects can be divided into three categories: those whose orbits are influenced by Neptune (unstable), those whose orbits are not influenced by Neptune (stable), and those whose orbits are extreme in their perihelia distances (farthest point from Sun in orbit) even for extreme Trans-Neptunian Objects (known as Sednoids).<\/p>\n

As more eTNOs \u2014 albeit a small sample size \u2014 were discovered in the early 2010s, an interesting pattern in the argument of perihelia and the direction of the orbit of some, but not all, eTNOs emerged: they were in alignment, or clustered.<\/p>\n

Several hypotheses were put forward to explain such observed clustering, including an examination of potential observational bias which would lead to the conclusion of clustering when in fact a more uniform distribution is actually present yet not observed.<\/p>\n

One of the proposed hypotheses was a super-Earth-type planet roughly 10 times the mass of Earth and in an extreme orbit with a semi-major axis of 400-800 AU.<\/p>\n

\"\"<\/p>\n

Planet 9 prediction based on the original six eTNOs with proposed clustering observations. (Credit: Caltech and Wiki Creative Commons)<\/p>\n

Additional work on that hypothesis conducted in part by Mike Brown and Konstantin Batygin showed that the theoretical existence of a 10 times Earth mass planet in the outer solar system would not just account for the observed clustering of certain eTNOs, but also potentially explain the presence of the Sednoid population of high perihelia objects while also proposing other dynamical elements to the outer solar system which have now been observed. <\/p>\n

As related by Dr. Konstantin Batygin, Professor of Planetary Science, Division of Geological and Planetary Sciences, CalTech, in an interview with NASASpaceflight, \u201cThe Planet 9 model actually sits on about four different pillars.\u201d <\/p>\n

Those include the clustering of some eTNO orbits, the existence of the high perihelia Sednoid objects, the high inclinations of eTNOs with orbits perpendicular to the orbits of the eight known planets, and the presence of high-inclination trans-Neptunian objects with semi-major axis less than 100 AU.<\/p>\n

So let\u2019s fast forward to earlier this month when Napier et al.\u2019s piece brought a larger focus back to Planet 9 with the publication of a paper titled: No Evidence for Orbital Clustering in Extreme Trans-Neptunian Objects<\/i>.<\/p>\n

Reactions to the paper ran the expected gamut, with some arguing it further weakened the theoretical argument for the planet\u2019s existence, others arguing it proved the planet didn\u2019t exist at all, while some cautioned that the paper didn\u2019t actually disprove what the title claimed and that there was still strong evidence for Planet 9.<\/p>\n

First: does the Napier et al. paper disprove orbital clustering of eTNOs?<\/p>\n

No, it does not \u2014 which the author\u2019s themselves point to in the conclusion of their paper: \u201cThis work also does not analyze whether some form of clustering could be consistent with the 14 eTNOs we consider.\u201d<\/p>\n

Importantly, too, the new analysis from Napier et al. doesn\u2019t disprove Planet 9, as the authors also address in their conclusion.  \u201cIt is important to note that our work does not explicitly rule out Planet X\/Planet 9; its dynamical effects are not yet well enough defined to falsify its existence with current data.\u201d<\/p>\n