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Home / Science / Planet 9 hypothesis receives a boost | space

Planet 9 hypothesis receives a boost | space



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  An artist's work depicting a dark half moon planet, far from a tiny sun against the backdrop of the Milky Way.

Artist's concept of what Planet 9 might look like if it exists. Picture via R. Hurt (IPAC) / Caltech.

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Does a large planet 9 ̵

1; a hypothetical planet that is many times the mass of the Earth in the far outer reaches of the solar system – really exist ? This question is still hotly debated by astronomers. Some say that a large planet 9 could explain the strange orbits of some of the smaller known bodies in the Kuiper Belt. Others say that these orbits could be caused by several unknown smaller bodies instead.

Several astronomers have recently reviewed the evidence for Planet 9 in an article published in February 2019 by Physics Reports . This peer-reviewed journal aims to publish in-depth and in-depth reviews of current topics in physics that are more extensive than just literary surveys. The article is called The Planet Nine Hypothesis and the astronomers who wrote it are still very optimistic that Planet 9 will eventually be found and confirmed. According to co-author Fred Adams of the University of Michigan:

The strongest argument for Planet 9 is that independent lines of evidence can all be explained by a proposed new planet with the same characteristics. In other words, there are several reasons to believe that Planet 9 is real, not just one.

From the review article in Physics Reports :

Polls over the past two decades have revealed the complex orbit of the Kuiper Belt, a field of icy bodies that orbit the Sun beyond Neptune. In addition to a variety of easily predictable orbital behaviors, the emerging count of trans-Neptunian objects shows dynamic phenomena that can not be explained solely by interactions with the well-known eight-planet solar system.

  Diagram of Kuiper Belt and Planet 9 orbits Another shows Planet 9 in about half the size of Neptune.

Charts showing the calculated orbit of Planet 9 in the outer solar system – much further than Neptune – and the estimated size compared to the other planets. Picture via James Tuttle Keane / Caltech.

Planet 9 – so-called because Pluto is no longer officially considered a major planet – was first adopted by astronomers Konstantin Batygin and Mike Brown of Caltech three years ago. Its existence could explain the odd orbits of some objects in the Kuiper Belt called Trans-Neptunian Objects (TNOs). The orbits of these small bodies are bundled in a way that suggests to some astronomers that a larger and more distant world (a planet 9) has dragged on them with their relatively strong gravity.

Mike Brown stated that the new review paper does not prove the existence of Planet 9. But he said:

… it suggests that the hypothesis is based on a solid foundation.

In an earlier article published on January 22, 2019 in The Astronomical Journal astronomers have calculated this The likelihood that Planet 9 did not exist was only 1 of 500.

If it is real, it is estimated that Planet 9 is about 5 to 10 times Earth's mass, possibly similar to the Super Earth type – exoplanets – larger than Earth, but smaller than Neptune. If this is the case, Planet 9 can be in an elongated orbit, reaching 400 times the Earth's distance from the Sun. that is very far away! The orbit is also calculated to be 15 to 20 degrees from the main orbital plane, in which most other planets form the orbit.

  Drawing the orbits of 6 Trans-Neptunian objects shows them bundled.

The orbits of six extreme trans -nepropical objects (in magenta) are mysteriously unidirectional, a configuration that some astronomers explain by the presence of a planet 9. Picture about Caltech / R. Hurt (IPAC).

Planet 9 was not easy to find – assuming it's actually there – so how long could it take for to finally be found ? Adams believes that within the next 10 to 15 years, astronomers will either confirm that Planet 9 exists or refute it from the data. He said:

With its proposed properties, Planet 9 is right on the edge of the observable. However, this is a very weak object in a very big sky. Since we do not know exactly where he is, you have to observe all or part of the sky to find the planet.

Over the next 10 years we will go deeper and deeper – which is more sensitive – Heavenly surveys. I think by 2030 we will have seen it or have a better idea of ​​where it is. Of course, it is also possible that until then we could have alternative explanations for the observed orbital anomalies.

Juliette Becker is a PhD student at the University of Michigan Department of Astronomy and co-author of the new review paper on Planet 9 She believes that the discovery of Planet 9 would help answer various secrets of the solar system, including the origin of the rocky object with the denomination 2015 BP519 and the nickname Caju. This object is one of the TNOs that is believed to be influenced by Planet 9 due to gravity. It has a diameter of just 550 miles (550 miles) and is located on an eccentric and inclined orbit. She said:

Planet 9 is a really good explanation for the 2015 BP519. The physics works flawlessly. But until we see Planet 9 in a picture and are sure that he is there, I do not feel that we have really solved the mystery of his origin. The presence of Planet 9 would respond to several seemingly unrelated open questions about the solar system in a beautiful and coherent way. I look forward to the day when we either see it or rule it out to finally answer these questions.

Incidentally, there is even a theory that Planet 9 could be an exoplanet – such as a super-earth. that was "stolen" by the sun from a nearby star. So you see, astronomers are really baffling the orbits of these outer bodies of the solar system. They are looking for ideas to explain them.

When a Planet 9 is found, it becomes one of the most exciting space discoveries in history. Ever since Pluto lost its most important planetary status in 2006, Neptune has been considered to be the sun's farthest planet from the Sun. If this is not the case, if another large planet – a planet 9 – exists, then astronomers have an unprecedented opportunity to learn more about how our solar system originated and evolved.

  Smaller earth next to the blue planet over two Earth's diameter.

Artistic concept of the size of the earth compared to the super-Earth 55 Cancri e. If Planet 9 exists, it may be similar to this distant exoplanet. Picture about NASA / JPL-Caltech / R. Hurt (SSC). Conclusion: The search for Planet 9 is – if it really exists – still a difficult task for astronomers, but the new study in Physics Reports reflects the continuing optimism of astronomers, will be found in a relatively short time.

Source: The Planet Nine Hypothesis

About the University of Michigan

  Paul Scott Anderson


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