The discovery of the ninth planet of the solar system by two astronomers from the California Institute of Technology in Pasadena became known on January 20. One of them - a native of Russia Konstantin Batygin - told "Lenta.ru" about the search for Planet X, the difficulties with the name of the new celestial body and about the unsolved mysteries of the solar system.
What is the planet you discovered?
Konstantin Batygin: It does not fall into the category of dwarf planets. This celestial body is quite massive. Our model gives a mass of about ten Earths, this planet is just gigantic. It is now defined as a celestial object whose gravitational field dominates that part of the solar system.
Konstantin Batygin
Photo: Damian Dovarganes / AP
In general, there is not even a question: is it a planet or not. We know about it because its gravity affects the orbits of distant objects in the Kuiper belt. The very mathematical modeling relies on the fact that this planet has sufficient mass in order to gravitationally dominate the solar system.
And its physical properties?
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The calculations, unfortunately, only give us the mass and general characteristics. We can only assume that it is similar in chemical composition to Uranus or Neptune. More precisely, we will say something when a device like New Horizons is sent to the planet. Although the flight is far, and the wait will take a long time
Where did Planet X come from?
We believe that it formed in the first three million years of the solar system, that is, about 4.5 billion years ago, from about the same material as Uranus and Neptune. While the solar system was still enveloped in a cloud of gas, this planet was gravitationally dispersed into a longer orbit.
Were you guided by Chadwick Trujillo and Scott Sheppard's observations of the 2012 VP113 trans-Neptunian object in 2004?
We relied on their work. What they found is called the argument of the perihelion of many orbits in the Kuiper belt. It turns out that this is only part of the story. The reality is an order of magnitude simpler and more fundamental: further orbits in the Kuiper belt point in approximately the same direction. Their physical orbits are practically the same. And it was this fundamental moment that led to the fact that we were able to calculate the orbit of "Planet 9".
Calculating the location of planet X
Image: NASA / JPL-CALTECH
How quickly do you hope to discover the planet with the Subaru telescope? Your colleagues, such as Professor Hal Levison, cannot wait for direct observation
In principle, we get the results from one night of observations rather quickly. The problem is that you need a lot of nights: you need to survey a fairly large part of the sky. So I think if we integrate, we will have to spend two to three years to find the planet that we predicted.
Does this planet have satellites?
We think so. My colleagues and I agree that there is no reason that would prevent this. Can they be seen in a telescope? Probably. But it's difficult …
Have you ever wondered what to name your new planet?
We with Mike Brown (Mike Brown, co-author of Konstantin Batygin - approx. "Lenta.ru") believe that it is better to entrust the world community. It's not for the two of us to decide. Again, we haven't thought about it yet: we have a theoretical model, but the planet has not been found astronomically.
Could other planets be found in the solar system?
I guess, yes. There is nothing that contradicts this possibility. But at the moment we do not have any data indicating that, besides the ninth planet, there is something else.
When will observational astronomy put an end to this story?
Good question. By the middle of the 20th century, observational astronomy seemed to have completed its work in the solar system. It turned out that this is not the case.
Kuiper Belt
Photo: wikimedia.org
In principle, the solar system is huge, the sun's gravitational field dominates very far: the dominant ends somewhere after one hundred thousand astronomical units, and we see small objects in the Kuiper belt at a maximum distance of eighty astronomical units. A huge space remains unknown.
Three major telescopes are under construction on Earth at once: the Giant Magellanic Telescope (GMT), the Thirty Meter Telescope (TMT) and the European Extremely Large Telescope (E-ELT). Will they be useful in such studies?
The projects you named are certainly important. However, telescopes like Subaru, whose cameras are designed to cover most of the sky, are more suitable for finding planets like ours. The same TMT will be good for characterization and bad for searching.
What if the discovery of the ninth planet is not confirmed?
The most dramatic precedent is the discovery of Neptune in 1846 by Urbain Le Verrier, who used mathematical models similar to those we have today. But our model is an order of magnitude more detailed and complex: it uses supercomputers.
And Le Verrier's calculations were confirmed in one night of observations.
Do you keep in touch with your Russian colleagues?
I lived in Russia until 1994, after which I moved with my family to Japan and then to the USA. I am mainly a theorist, sometimes I communicate by e-mail with colleagues from Russia and Russians working in the USA and other countries.
I do not read Russian media due to the lack of time. I try to deal exclusively with science. I can say that Russia remains strong in theoretical science: there are many good scientists. The story of Mikhail Lidov comes to mind, who in the 1950s calculated the effect that is now called the "Lidov-Kozai resonance". For a long time people did not understand how important this effect is. Lidov was dozens of years ahead of humanity, and there are still such scientists in Russia.
How long have you been working on the Planet X article that appeared in The Astronomical Journal?
We took on this task about a year and a half ago, and wrote the article in November, completing it after a night at the telescope.
How quickly did you get through the review?
Fast enough. That is, after we submitted the article to the journal, two months have passed, which is very short for such things.
Mike Brown and Konstantin Batygin
Photo: Damian Dovarganes / AP
I believe that arXiv.org and open-access magazines are one of the main trends. I try to publish in magazines of this particular format or in those that immediately post articles in open-access.
Is publishing an article about the discovery of the planet in The Astronomical Journal essential?
We decided not to contact Nature or Science. We wanted to write about everything in detail, but the format of these magazines does not allow for this.
Don't you think influential researchers like Stephen Hawking are pushing other scientists out of the media?
To be honest, I read the last article by Stephen Hawking only peripherally. I'm sure it's important. Problems are everywhere, but a good scientific article will always be noticed by whoever wrote it.