A new discovery reinforces the notion that a large, mysterious planet – known as Planet 9 or Planet X – could lurk invisibly on the edge of the solar system. Astronomers say they have found a small object that is far from the Sun and fits the Planet X theory. In fact, the object may even have been pushed on the path that the gravity of this hidden planet is now taking.
The tiny stone – eloquently called TG387 and nicknamed "The Goblin" – was discovered by astronomers at the Carnegie Institution of Science, a huge Japanese observatory in Hawaii called Subaru. The Carnegie team first discovered the property in 201
This orbit is particularly tempting as it puts TG387 into a selection of solar system distant objects, all pointing to the possible existence of Planet X. point out. There are currently 14 distant space rockets, all of which have similar orbital patterns, suggesting that this planet is out there. Their paths are all superlong, and they all group in the same area as they approach the sun. Moreover, their orbits are all equally tilted, pointing in the same direction as if something great had pushed them into similar places. These objects are the strongest evidence astronomers have for Planet X, and the search for a new one that matches this pattern reinforces the notion that this planet is more than just a theory.
In addition, each new find helps astronomers find the planet X. "Each time we find another of these smaller objects, it will make us assess where the larger planet might be," reports Scott Sheppard, astronomer at Carnegie Science and lead author of a study in The Astronomical Journal on the discovery tells The Verge . "They are all in very similar orbits, but their orbits are all slightly different [limits] where the planet could be."
The idea that a huge planet lurking beyond Neptune is an idea that astronomers have speculated for the last century. But the hunt for this planet became much more serious in 2012, when Sheppard and his team found a widely scattered object that was truly unique. It was an object called VP113, and it currently contains the record for the farthest object orbiting the Sun. The nearest star closest to the star is 80 AU or 80 times the Earth-Sun distance. Sheppard noticed that this object also followed a path similar to those of some other distant space rock and a distant dwarf planet called Sedna. "They all have this accumulation, so they hinted that something was driving them into similar types of lanes," says Sheppard.
Then, in 2016, a pair of Caltech researchers, Mike Brown and Konstantin Batygin, has calculated the math. Based on the orbits of six of these objects, they estimated that there is a planet about ten times the mass of the Earth that goes far beyond Neptune. Their calculations showed that it may take 10,000 to 20,000 years to orbit the sun. Brown and Batygin called the phantom planet Planet 9, though others called it Planet X years ago.
Since then, more and more objects have been found that fit into this orbit pattern. The idea is that these objects have exactly the right orbits to survive the planet X's gravity wrath. If they followed another path, they would probably collide with the big planet, or the planet's gravity would shoot them out of the solar system. However, all these very distant objects orbit so that they never approach the planet X when crossing their orbits. "Whenever the planet crosses the orbit of one of these objects, these objects are on the other side of the solar system, so they never come close," says Sheppard.
But not all of these objects are as reliable narrators as they could be. "Some of these 14 objects tell a more precise story than others," says Batygin, who was not involved in today's study, The Verge . First, some of the objects traverse the orbit of Neptune, and the gravity of this planet can affect the objects and deform their routes. "Neptune has the effect of darkening things, even if you have a Planet 9 carefully crafted orbit." This makes it difficult to know if the object is actually being moved by this invisible planet.
But this new discovery, TG387, is particularly so because its orbit is so far away. When it is furthest from the sun, the rock is at the extreme 2300 AU. In fact, it is remarkable that astronomers have found everything because it is seven times smaller than Pluto and so far away. However, due to its extreme distance, TG387 is in no way affected by the large objects in the inner solar system. Jupiter, Saturn, Uranus and Neptune do not affect their orbit. That is, if this object is really orbited by Planet X, it could contain more information about the planet's orbit than other objects. And when the team did simulations of the solar system with a Planet X in it, they found out that the orbit of that object can not change. "This joins an elite group of six stable objects," says Batygin.
Of course Planet X is far from finished. There are only 14 objects that potentially support its existence. This is a very low number according to statistical standards. "We do not have many of these objects," says Michele Bannister, an astronomer who studied distant small bodies at Queen's University in Belfast, who was not involved in this research The Verge . "I would be very happy if we had tens, but there are hardly a handful." In addition, Bannister says it is important to remember that astronomers still do not have a comprehensive snapshot of the distant solar system. The season, the weather, and the part of the sky that a telescope observes affect all kinds of objects that are detected there, which further affects the sample.
In addition, the objects we find are typically close to the Sun on their super-distant orbits, which skews our discoveries a bit. For example, TG387 was found when it was about 80 AU away, not thousands of AUs away. This means we do not have a good idea of what's out there because we can not see the objects that are out in their tracks. "Each of these objects we discover is the tip of an iceberg for a larger population," says Bannister. Every new discovery requires hundreds of thousands of objects that astronomers can not see. And these objects may tell a different story from Planet X.
Bannister, who predicted that an object like TG387 might exist in the solar system, says that this discovery helps shape our understanding of the distant solar system. We still do not understand why there are such objects that are completely detached from the rest of the planets. "They have made a great discovery," she says. "These are exactly the objects we need to find to understand the origin and history of our solar system."