Does this discovery of ‘The Goblin’ make ‘Planet 9’ more likely? Yes I’d say so. It’s looking really strange. I’m beginning to be won around to the idea :). There is plenty of space for planets to exist beyond Neptune. No known big gas giants to get in their way. And – objects get far far fainter the further they are from the sun.
The thing is that our telescopes can spot even small objects easily out to about the distance of Pluto. But beyond there it rapidly gets very hard to see anything. It’s because of the way brightness falls off with distance. If something is ten times further away, it is visually 100 times smaller in the sky, and what’s more, it gets only a hundredth of the sunlight, and combining those two effects makes it 10,000 times fainter to our telescopes. Something a hundred times the distance of Pluto would be a hundred million times fainter. You can also look at it another way. If it is ten times further away its diameter has to be 100 times larger to be the same brightness (would make it 10,000 times larger in cross section to compensate for being 10,000 times fainter).
“Where we think the planet is—hundreds of AU away, if not 1,000 AU—something even as big as Neptune would be fainter than most telescopes could see,” Sheppard told Space.com. (In case this sounds odd or incongruous: The Goblin was discovered near perihelion, at about 80 AU from the sun.)
“And most of our surveys to date do not go that faint, do not go that deep. We’ve covered very little of the sky to the depth that’s needed to be covered to find something this faint,” he added. “You can hide a very big thing in the outer solar system very easily.” Newfound World “The Goblin” May Lead to Mysterious Planet Nine
From that same article, it was found at a distance of 80 au and has an estimated diameter of 300 km approximately (they don’t know for sure as it depends on whether it is light or dark coloured, they just know its total overall brightness).
If it was at a distance of 800 au, it would need to have a diameter of 30,000 km to have the same brightness. “Planet 9” if it exists would be 13,000 to 26,000 km in diameter and expected to be up to 1,200 au away. That would make it significantly fainter than Goblin. So, if it exists it is just on the edge of what is possible for our biggest telescopes to spot.
Artist’s impression of distant “planet 9” which the Goblin may be hinting at Introducing ‘The Goblin’: A new, distant dwarf planet bolsters evidence for planet 9
This shows its orbit
This shows some of the other objects found so far – “the Goblin” would be in an orbit stretching off to the left in this picture. It’s striking to look at, nearly all of them except 2013 FT28 are in orbits in that direction.
Postulated orbit of ‘Planet 9’ in green and the detached objects – note how the newly discovered objects cluster on one side of the sun – this could be due to the influence of a big heavy planet in the postulated orbit.
The theory is that the big planet 9 makes orbits in the other directions unstable over very long time periods – though you won’t notice anything in a single orbit. It’s not like the discovery of Neptune – we don’t see any anomalies in the movements of these objects
The only anomaly is that they are in these very elliptical orbits that cluster to one side of the sun. The orbits themselves, are normal enough; the anomaly is more about what we don’t find. Why haven’t we yet found any similar objects in ellipses pointing in the opposite direction?
Also notice that these objects were only discovered because they were at the closest part of their orbit to the sun.
It’s not remotely likely they all happened to be close to the sun by coincidence at the very moment in time that astronomers started looking for them. This means that there must be dozens, hundreds probably of these objects that are in similar orbits – but currently much further from the sun. We must be seeing only a small selection from a vast population of hundreds of these objects. And when there are so many objects of a few hundred kilometers in diameter up to a few thousands – you’d expect to find a few larger ones – so – there may well be larger Mars and Earth sized planets out there in similar orbits to Sedna as well as the “Planet 9”.
Mike Brown hypothesized that in a talk about Sedna soon after its discovery – that there are probably several Mercury, Mars and maybe even Earth sized objects out there in similar orbits to Sedna. These haven’t been found yet – but they would be even harder to spot than “Planet 9”. Though it doesn’t get mentioned much, this option is also surely very much in the air still. There has to be a largest object in these families and it is not at all likely we have found it yet – so how large is it?
So – we may eventually find not just ‘Planet 9’ but ‘Planet’s 10, 11, 12, …’. And – some of them – way out there beyond Pluto – may be as large as Mercury or as large as Mars or even Earth. The IAU will want to say they aren’t planets because they don’t “clear their orbits”. But I think we will surely call them planets and re-open that whole debate again.
This picture shows some of those objects again, but I like it because it gives an idea of our solar neighbourhood. Out to Jupiter we can spot objects as small as a few kilometers in diameter. out to Pluto – tens of kilometers through to hundreds of kilometers. But further out we could miss even rather large planets. Far enough out and we could miss even a planet as large as Jupiter.
“The four zones of the solar system include a staggering amount of unexplored space–almost everything beyond Pluto is barely known. (Credit: M. Brown/Caltech/R.Hurt/C.Powell)” (figure from this article)
There could be not just one big planet – there could be many – planets the size of Mars, the Earth, this ‘Planet 9’ the size of Neptune – and maybe even larger ones. We could miss Jupiter if you go out far enough from the sun. The Oort cloud stretches out much of the way towards the nearby stars. There could be objects orbiting a light year away or more.
Am object as large as Jupiter a light year away would not form in the manner of the other planets from the same blob of gas that collapsed to form our solar system. But it could form as a sub-brown dwarf – a planet that condenses out of a separate blob of material, in similar fashion to a binary star.
We do know that there is no companion second stars. The WISE infrared space telescope disproved that. No brown dwarfs either unless they are really really cold (unlikely) as they would be easy to spot by the heat radiation – can be seen up to ten light years away.
MIKE BROWN PREDICTION OF A FUTURE DISCOVERY OF A MARS SIZED DWARF PLANET NON PLANET BEYOND NEPTUNE
You may remember that the IAU declared that Pluto was not a planet some time back, because, they said, a planet has to “clear its orbit” of most other objects.
Here is his video where he predicts using a statistical argument from the orbit of Sedna, that we are likely to find planets beyond Neptune that are Mercury, Mars or even Earth sized. He then goes on to say.
“What is strange about this one, we happened to find this one almost at the closest point it ever gets to the sun. Not
by coincidence. Because there is only about a 200 period shown in red
here when we could have seen it. … So 200 years out of 12,000 years
means 1 in 60 chance of finding it. So either we are very lucky, which
astronomers don’t like to think of themselves as lucky, or scientists in
general, but instead what we like to think is that if we found
something and we only had a 1 in 60 chance of finding it, probably there
are 60 of them and we just found the one that happens to be close. …
Now maybe it’s not 60. Maybe it’s 30 and we got a little bit lucky.
Maybe it’s 90 and we got a little bit unlucky. But there are a lot of
objects in this very distant region where we never knew of anything
before. This is the first time we found anything in this region out
“”Now the fun thing to think about is, if
there are 60 of these, and Sedna is about 3/4 times the size of Pluto,
if there are 60 objects 3/4 the size of Pluto there are probably, oh, 30
objects the size of Pluto, that’s a lot of objects the size of Pluto.
There are probably 10 objects that are twice the size of Pluto and there
are probably two or three objects that are three and four and maybe
even five times the size of Pluto. in this region here. It’s a little
bit vague, since we have only found one object, to be able to
extrapolate to these things, but it is not that vague. There must be
some of these very large objects out there. And our big goal now, and
one of my current grad students PhD thesis is to find these objects, if
there are some big objects out there two or three or four times the size
of Pluto, these things are the size of Mercury, these things are the
size of Mars, these things are the size of the Earth. If you take that
final thought and you look at the kuiper belt and you put this object on
there, that’s the size of Mars,”
“I am willing to
go out on a limb there and say, we will find something like that, the
size of Mars, in this region of space. And scientifically, this will be
fantastic because we will get to learn about an entirely new class of
objects, and try to understand how they got there. But just as much fun,
of course, is that this will cause the astronomers to go into a tizzy
again. Because, if you find it, what do you call it? Well by the current
definition – and I forgot to tell you of course, the current definition
is, you have the eight planets, and if you are not a planet but you are
still one of those round things, you are a dwarf planet. ”
a weird word because there are very few cases in the English language
where you have adjective, noun, combination “dwarf planet” is not a
“planet”. Dwarf planets are not planets. They are dwarf planets. But by
the official definition this object the size of Mars would be a dwarf
planet. I actually believe that that’s the right classification. Because
I still think that this population deserves to be put together and the
planets are actually special. But I don’t think most people are going to
buy that. I think if you find something the size of Mars, something the
size ofthe Earth, I think most people are going to want to call it a
planet, and I think astronomers are going to get in an uproar again.
Maybe they will have as much fun as they did in Prague….”
and goes on to speculate about the future IAU meeting after astronomers find a Mars sized Dwarf Planet Non Planet according to the IAU definition.
The video is here
‘Planet 9’ if it exists would just sneak in as orbit clearing
The vertical axis shows its mass in Earth masses.
At the distance of ‘Planet 9’ none of the terrestrial planets, not even Earth would count as orbit clearing. If there was a planet as big as Earth with a semi-major axis as large as Sedna, or ‘the Goblin’, it would not count as a ‘planet’ according to the IAU.
You can also see from this diagram that both Pluto and Eris would count as planets if they were in the same orbit that Mercury is in now, and that Mercury would be right on the boundary at the distance of Pluto and well below it at the distance of Eris. Meanwhile, a sub-brown dwarf the size of Jupiter would not count as orbit clearing if it formed more than a light year away from our sun.
THESE NEW PLANETS, IF FOUND, CAN’T COME INTO THE INNER SOLAR SYSTEM
Planet X is a general term for any hypothesis for a planet that hasn’t been found yet. Pluto was the first “planet X” before they found it. There have been many since then, most of which were disproved, for instance Robert Harrington proposed a planet to explain anomalies in the orbit of Neptune. The need for it went away when Myles Standish recalculated the mass of Neptune after the Uranus flyby, and the anomalies vanished, and since then all the planets in the solar system are behaving exactly as predicted.
Neptune would have been called ‘Planet X’ before it was discovered if they had had that terminology then. I think it was Lowell who started the search for Pluto who first came up with this. X stands for “unknown”.
If you search for news about ‘Planet X’ then google fills your search page with search results about ‘Nibiru’, a mythical planet that cannot exist. Here is planet x -bikes – Google Search (to exclude the ‘Planet X’ bike company from the searches).
Two out of the top three search results claim that ‘The Goblin’ could prove that ‘Nibiru’ exists. If you are an amateur or professional astronomer you may never have heard of ‘Nibiru’. It is an absurd conspiracy theory that there is an extra planet in our solar system that is about to hit Earth or flyby Earth. They have been claiming it will do this ever since 2003 since a lady Nancy Lieder claimed that extra terrestrials from the Zeta Reticuli – Wikipedia star system 39 light years away told her about ‘Nibiru’ through an organic implant in her brain. Of course nothing happened.
This is because Google is rubbish at filtering out fake science news about planets.
The conspiracy theorists claim that all these disproved planets were the same planet ‘Nibiru’ – including Robert Harrington’s ‘Planet X’. They claim he was murdered to hide the news (actually his theory was disproved six months before he died of throat cancer). They ignore such differences such as the hypothetical planets since Pluto orbit permanently way beyond Neptune.
In principle a planet could cross Neptune’s orbit – Pluto does – by being in a resonance, a 3:2 resonance. There are many others known now, in resonances of 1:2. 1:3, 1:4, 1:5, 2:3, 3:5, 2:5, 4:7 and various other ratios, collectively called the resonant trans Neptunian objects.
An object can’t be in resonance with both Neptune and Uranus though because those two planets are not in resonance with each other. That’s why any planet or dwarf planet that comes as close as Uranus won’t last long.
One that crosses all the gas giants and reaches Earth’s orbit couldn’t last a million years. If it is a brown dwarf it is even worse, all the other planets would be gone within a million years, indeed very quickly, even just one flyby of the inner solar system would disturb it so much that the planets would be in bizarre elongated orbits, probably swap orbits and so on. They would soon hit the Sun, ‘Nibiru’, or be ejected altogether.
So it is impossible our solar system has such a brown dwarf. And a planet smaller than Jupiter would have had very obvious effects on Earth’s orbit and we’d have probably have lost our Moon too if it had buzzed Earth 3600 years ago. The idea is just absurd, LOL silly to astronomers and has been since Newton first figured out the mathematics of gravity, that planets follow the inverse square law of attraction..
See also my
See also my