Another planet in our solar system?
Scientists believe that a ninth planet almost certainly exists deep within our solar system. A celestial body currently dubbed “Planet Nine” is believed to lie beyond the Kuiper Belt – a layer of asteroid-like ice rock that begins near Neptune’s orbit and continues outward beyond. beyond the orbit of the dwarf planet Pluto, and into the far reaches of the solar system.
It is after this layer that Planet Nine should sit, if at all. The existence of Planet Nine could provide explanations for a series of unlikely clusters of objects beyond Neptune. Since Neptune is the last known planet in the solar system, objects beyond (but still in our solar system) are known as transneptunian objects (TNO). Objects that are even much further away than these – and which are considered to be of considerable size – are known as extreme TNOs (or ETNOs). Planet Nine could explain the otherwise highly unlikely clustering of some nearby ETNOs.
One of the researchers closest to this project is Michael E. Brown, professor of planetary astronomy at Caltech. Brown was the man responsible for the demotion of Pluto from a planet to a dwarf planet, due to its size. Brown and his colleague at Caltech, Konstantin Batygin, suggested that planet nine may have formed from the core of a previous planet that collided with the solar system’s largest, Jupiter, at the very beginning of the formation of the solar system – the nebula hypothesis.
A number of fear-mongering articles have been written on this topic claiming that Planet Nine could send asteroids and comets flying towards Earth, which could trigger the end of life on our planet. There is no evidence for this. The only way Planet Nine has interacted with other objects is by influencing the little icy bodies much, much closer to Planet Nine itself. It is wrong to say that the Earth would be in danger if Planet Nine existed.
Regardless of this fake news, Planet Nine is an exciting proposition for scientists. It is estimated to have a radius of between 2 and 4 times the size of the Earth and a mass of 4 to 8 times that of the Earth. This would make Planet Nine one of the largest planets in the solar system, and make its history – whether aligned with Batygin and Brown’s hypothesis for its formation or not – a gripping and eventful one.
As you might expect, one of the most controversial topics surrounding Planet Nine is its name. It is only once there are images showing that the planet exists that it will receive a formal name. Therefore, his placeholder remains ‘Planet Nine’ for the time being. While Greek and Roman mythology tends to be used for planetary names, there is not much precedent for the name of the planets. Only two planets in the solar system have been discovered in history: the two most distant, Uranus and Neptune.
However, some are not even happy with the use of “Planet Nine” in the meantime. Between the discovery of Pluto by Clyde Tombaugh in 1930 and its withdrawal from planet status in 2006, it was the ninth planet from the Sun. This led US planetologist Alan Stern to comment in 2018 that the reuse of the name ‘Planet Nine’ is “an effort to erase the legacy of Clyde Tombaugh, and that is frankly insulting.”
Some have suggested that the name “Persephone” could be used for Planet Nine if its existence is ever confirmed. The name is often used as a name for fictional planets farther from the sun than Neptune. This is due to the fact that in Greek mythology the wife of the deity Pluto is called Persephone. However, it is unlikely that “Persephone” will ever become the official name of Planet Nine, as there is already an asteroid called “399 Persephone”, which was discovered in Heidelberg, Germany, by Max Wolf in 1895.