Giant, weird orbit, debate ... there can be only one name. This is Planet X.
Also because X would be 10th discovered planet, a reference that pluto, while not a planet today, was indeed the ninth _discovered_ planet.
Caltech Researchers Find Evidence of a Planet Beyond Pluto
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Re: Caltech Researchers Find Evidence of a Planet Beyond Pluto
#22> * the putative ninth planet—at 5,000 times the mass of Pluto—is sufficiently large that there should be no debate about whether it is a true planet* That's 10x the mass of the Earth, right, or about 3x the size of Neptune?
10x the mass of earth is about 60% of the mass of Neptune or 80% of the mass of Uranus. So it's smaller than all of the gas giants in the system, but considerably larger than the rocky planets.
Re: Caltech Researchers Find Evidence of a Planet Beyond Pluto
#23More from the folks behind the paper: http://www.findplanetnine.com/
Re: Caltech Researchers Find Evidence of a Planet Beyond Pluto
#24If it holds up, this is fantastic. Given how interesting the Pluto system has turned out to be, I can only fantasise about a potential super-earth system relatively nearby. However, to be completely pedantic: would this actually be a planet ? Or still a dwarf planet , despite its massive size? Keep in mind that the definition of planethood is not only that it's large enough to be rounded by its own gravity, but that…
From what I understand, it has cleared the space but there are still harmonic crossings that can't be cleared. Interesting challenge to the new definition - must the orbit be clear, or only clear sailing through the orbit.
Re: Caltech Researchers Find Evidence of a Planet Beyond Pluto
#25> Batygin and Brown inferred its presence from the peculiar clustering of six previously known objects that orbit beyond Neptune.
This raised a big red flag in my mind. This must produce a literally astronomical multiple comparisons problem. Yes they reported sigma = 3.8, but if they didn't do their multiple comparisons correction right (which I am in no position to determine), they're basically reading tea leaves.
If you're not familiar with multiple comparisons, it's kind of like [this](https://www.goodreads.com/quotes/649893-you-know-the-most-am...) or [this](https://xkcd.com/882/). If you look at enough extra-neptunian bodies, some of them are going to be in an odd looking cluster.
Re: Caltech Researchers Find Evidence of a Planet Beyond Pluto
#26I'm puzzled by how a planet this big could form in an orbit so distant. The fact that the material in that region is so spread out and the orbital period of such object is so long matters. I would love to read some thoughts on that.
As mentioned in the article, this planet could have formed closer to the sun before getting thrown out by Jupiter/Saturn.
Re: Caltech Researchers Find Evidence of a Planet Beyond Pluto
#27Ah Planet X which is now planet IX with Pluto's demotion :-). I am guessing that you can confirm it by looking for star occulusions. Presumably the planet would blank out stars as it passed between earth and those stars. So would it be possible to find it using existing plates?
It is pretty well impossible to discover a planet by occultations. For one thing, in most parts of the sky the density of stars is pretty low. People do study occultations by known distant objects -- that provides some of the best available info on physical size and presence of atmosphere for KBO's. But in most parts of the sky, it is years in between occultations, which last just minutes. You have to be looking in the right place at the right time. And the sky is full of variable stars, so just looking for changes is hard.
Re: Caltech Researchers Find Evidence of a Planet Beyond Pluto
#28If it holds up, this is fantastic. Given how interesting the Pluto system has turned out to be, I can only fantasise about a potential super-earth system relatively nearby. However, to be completely pedantic: would this actually be a planet ? Or still a dwarf planet , despite its massive size? Keep in mind that the definition of planethood is not only that it's large enough to be rounded by its own gravity, but that…
> However, to be completely pedantic: would this actually be a planet?
This is one of the paper's author's answer to that question.
http://www.findplanetnine.com/2016/01/is-planet-nine-planet....
Re: Caltech Researchers Find Evidence of a Planet Beyond Pluto
#29Did anyone else notice that the rendering of the orbits in the article looks strikingly similar to Kerbal Space Program's orbit UI?
Re: Caltech Researchers Find Evidence of a Planet Beyond Pluto
#30For a moment there, I thought of Nibiru :D