More planets for the ‘Sol’ system?
Are there more planets outside the orbit of Neptune? Two papers published in the Royal Astronomical Society Letters seem to indicate that there indeed may be at least two more planets beyond Neptune. These trans-Neptunian objects (TNO) have yet to be directly observed, but numerical calculations by astronomers at Complutense University of Madrid and the University of Cambridge seem to indicate their existence. The scientists think there must be at least two planets based on the orbital behavior of extreme trans-Neptunian objects (ETNO).
The most accepted theory establishes that the orbits of these objects should be distributed randomly. The object’s paths must also fulfill a series of characteristics. including having an inclination of almost 0° and an argument or angle of perihelion (closest point of the orbit to our Sun) close to 0 degrees or 180 degrees, a semi-major axis with a value close to 150 AU (Astronomical Units or approximately 14 billion miles).
“This excess of objects with unexpected orbital parameters makes us believe that some invisible forces are altering the distribution of the orbital elements of the ETNO and we consider that the most probable explanation is that other unknown planets exist beyond Neptune and Pluto,” says Carlos de la Fuente Marcos, astronomer at the UCM and a co-author of the papers.
The technique is not without controversy. The sample size for this study is quite limited with only 13 objects used in the analysis. Even the authors of the study admit that this is a limitation and impacts the accuracy of their claim. By publishing these papers, they are hoping for active engagement in expanding the search and that eventually more ETNOs will be cataloged and added to improve the analysis.
Additionally, this study clashes with the current predictions for solar system formation. None of the current models use planets beyond the Neptunian orbit to describe the orbital perturbations of ETNO. The discoverers acknowledge that these two issues need further research and clarification before a more solid model can be created.
The team does have a bright point of encouragement due to a recent announcement. A planet forming disk more than 100 AU from the star HL Tauri has been discovered by the Atacama Large Millimeter/submillimeter Array (ALMA ) radio telescope. This disk suggests that planets may indeed be capable of forming at large distances from their host star. This may alter the current planet forming models and provide a basis for further ETNO research.
Joe Latrell is a life-long avid space enthusiast having created his own rocket company in Roswell, NM in addition to other consumer space endeavors. He continues to design, build and launch his own rockets and has a passion to see the next generation excited about the opportunities of space exploration. Joe lends his experiences from the corporate and small business arenas to organizations such as Teachers In Space, Inc. He is also actively engaged in his church investing his many skills to assist this and other non-profit endeavors.