Even though Pluto may not be considered a planet anymore, the number of planets in the Solar System may increase soon. British and Spanish astronomers believe there are two more planetary entities that are to be discovered far beyond Neptune, the furthest planet from the Sun. Although these may not be normal-sized planets that people will be able to see without a telescope, astronomers say they may lurk among the thousands of other rocky masses where the former planet Pluto is located.
In the latest edition of Monthly Notices of the Royal Astronomical Society, a British astronomy journal, scientists predicted that there are two distant bodies that display unusual orbital behavior. The area where these are located is called the trans-Neptunian region. These extreme trans-Neptunian objects (ETNOs) are located beyond 150 astronomical units (AU) from the Sun but should relatively follow the Sun’s orbit to be considered as a part of the relevant Solar System.
An astronomical unit is a distance measurement used to calculate the vast distance between planets in the Solar System. One unit is based on the distance from the Sun to the Earth – 93 million miles. Therefore, 150 astronomical units equals 13,950,000,000 miles. To show the great distance from the Sun the ETNOs are, Neptune is 30 AU away from the Sun and Pluto is around 40 AU.
Even though the ETNOs should follow the basic motion of the Sun’s gravitational pull, astronomers scientists have observed around 12 masses that display orbital movement that does not follow the path which masses in that region should. Scientists have learned that the abnormal orbits suggest the trans-Neptunian region may be much larger than previously thought. Scientists believe that the most outer region may extend far beyond 150 AU to around 525 AU.
There are varying orbital inclinations of the anomalies, from 0 to 20 degrees. To explain this irregularity, their analysis suggests that a few larger than normal objects – planets – must be within the distance of the ETNO to exert gravitational force upon them.
Astrophysicist Carlos de la Fuente Marcos, of the Complutense University of Madrid, explained that there was an abnormally large number of objects which were outside of expected orbital norms, and that this led his team to believe that there were other bodies exerting forces that were altering how they were distributed.
Astronomers will be able to examine and analyze the size of the anomaly by calculating the irregular orbits of ETNOs and link them back to a reference point that would be a constant on all masses in question. The analysis would be able to determine what the anomaly is, how big it is, and how many there are if applicable. Current predictions indicate that there are at least two potential planets in the region.
Marcos’ team, along with astronomers from the University of Cambridge, have created a model based on gravitational perturbations previously observed when comet 96P/Machholz 1 travelled by Jupiter, the largest planet.
The initial findings from Marcos’s team using this model showed that irregular orbital movement from one potential planet at 200 AU was consistent with another located at around 250 AU.
Although there is no concrete evidence to support this claim, only theory, the research team stated, “If it is confirmed, out results may be truly revolutionary for astronomy.”
By Alex Lemieux
Feature Image courtesy of Karen Blumberg – Flickr License