Planet Nine

The astronomical field of science was forever changed when on August 24, 2006, Pluto was demoted from planet to dwarf planet. This move was considered controversial by many, and for those that grew up learning that Pluto was a planet, is a subject of contention to this very day. So the recent data showing the possibility of a ninth planet existing in the Solar System after all will no doubt be a cause for celebration for some. 

    Researchers Konstantin Batygin and Mike Brown at the California Institute of Technology, in a recent article published for The Astronomical Journal, have recently discovered evidence that a potential ninth planet may exist beyond even the orbit of Pluto. While the planet has not been observed directly, mathematical modelling and computer simulations have been able to calculate the planet’s possible size and orbit. 

    In an article posted on the California Institute of Technology’s official website, Brown stated that this would be the real ninth planet. "There have only been two true planets discovered since ancient times, and this would be a third. It's a pretty substantial chunk of our solar system that's still out there to be found, which is pretty exciting." 

    The paper outlines an argument for this planet based on a half-dozen smaller distant space bodies orbiting elliptically. Rather than rotating like other standard objects that far out in space, they had a peculiar orbit around the Sun. After several tests and various computations, Batygin and Brown came to the conclusion that it is possible that a planet might exist far beyond the bounds of what is normally thought of as the Solar System. A planet outside of the belt of ice and space debris beyond Neptune (known as the Kuiper Belt) would help explain why these distant bodies have such unusual orbital patterns. "Although we were initially quite skeptical that this planet could exist, as we continued to investigate its orbit and what it would mean for the outer solar system, we become increasingly convinced that it is out there," said Konstantin Batygin, “"For the first time in over 150 years, there is solid evidence that the solar system's planetary census is incomplete.”

    According to their paper, in order for their calculations and their data to be correct, this potential ninth planet would be at least the size of Earth, though more than likely it would be bigger though still smaller than Neptune. It also would have to have a small atmosphere with a rocky core and approximately 4.6 billion times the mass of Pluto. The research paper also states that this ninth planet, at its closest, would still be 20 billion light years from Earth, and it would take about 10,000 to 20,000 years in order for humans to arrive at it from Earth. 

    Where this potential planet might have come from and how it ended up in the Solar System can be explained by how the system was created in the beginning. According to the California Institute article, “Scientists have long believed that the early solar system began with four planetary cores that went on to grab all of the gas around them, forming the four gas planets—Jupiter, Saturn, Uranus, and Neptune. Over time, collisions and ejections shaped them and moved them out to their present locations.” Brown speculates that there is no reason why there could not have been another such core that could have gone farther out into space, perhaps by coming in to close with the gravity of Jupiter or Saturn, and ejecting it. That core would have eventually became this planet. 

    While this planet has yet to be observed by any telescopes, this research has the possibility to shake up the astronomical community. "All those people who are mad that Pluto is no longer a planet can be thrilled to know that there is a real planet out there still to be found," said Brown, “Now we can go and find this planet and make the solar system have nine planets once again." Their paper is titled “Evidence for a Distant Giant Planet in the Solar System”, and is available from The Astronomical Journal.