Scientists find more evidence of a ninth planet in our solar system 

Posted: March 29, 2016 by oldbrew in Astronomy, solar system dynamics
Tags: ,
The hunt for 'Planet 9' [image credit: Caltech]

The hunt for ‘Planet 9’ [image credit: Caltech]

Still no guarantee that such a planet exists, but the signs seem promising.
H/T Daily Mail Online

Since its discovery at the beginning of this year, the mysterious ‘Planet Nine’ has had scientists looking for the signs that could confirm its existence.

Now, astronomer Mike Brown of Caltech, one of the scientists behind the January announcement, claims he’s found further evidence to support it. The giant hidden planet is thought to sit on the edge of our solar system and is 10 times more massive than the Earth, gaseous, and similar to Uranus or Neptune.

Last week, Mike Brown tweeted a photo that shows the plot of a newly discovered eccentric Kuiper Belt Object (KBO).

In the post, Brown wrote: ‘Hey Planet Nine fans, a new eccentric KBO was discovered. And it is exactly where Planet Nine says it should be.’

The KBO in question is ‘uo3L91,’ shown with a solid blue line in the graph [see report]. Brown writes that the slide comes from a recent talk at the Seti Institute.

This discovery was made from an Outer Solar System Origins Survey (OSSOS) on the Canada-France-Hawaii Telescope, according to a subsequent tweet.

Planet Nine is oriented oppositely from the other planets, the astronomer explains, so it is off of the graph, and to the right.

‘I haven’t done the statistics yet, but I suspect this takes the probability of this being a statistical fluke down to ~.001% or so,’ Brown tweeted.

While no conclusive evidence of its existence has emerged so far, a number of researchers have undertaken their own studies on the possible planet, which is referred to as Planet Nine or Planet X.

Full report: Scientists say they have more evidence of a NINTH planet in our solar system | Daily Mail Online
[includes graphics and a video]

  1. oldbrew says:

    From the Independent: ‘A new finding continues to lend support to the theory that there is a ninth planet lurking at the edge of our solar system.’

  2. Judging by the image presented above, the planet (and the other 7 labelled orbits–of what?) is interstellar. What is one to make of that? Why would a serious, competent (aye, there is that word again) academic at a prestigious institution put out such a ridiculous image, which is on a par with a child’s comic book or one of those “worst sci-fi movies ever” (the only thing missing is a giant face of Galactus, drawn by Jack Kirby, covering the whole field of view). Even forgetting about the silly star field superposition. they don’t even indicate the ecliptic, which all the known planets follow closely in their orbits, and which DEFINES the solar system, along with the Sun at the “center”, in any reasonable illustration of it (even Pluto’s orbit is tilted only 17 degrees off the ecliptic, most are within 2.5 degrees of it). In short, there is simply nothing on the image to even show you’re looking at the solar system; there is nothing recognizable–which makes it meaningless in a story hyping a “ninth planet” IN the solar system.

  3. oldbrew says:

    Here’s a list of the ‘Most-distant known trans-Neptunian objects (TNOs) in the Solar System as of 26 February 2016’:

    For example 2012_VP113 (diameter 460 km.) has an inclination of ~24 degrees, so about a third more than Pluto.
    For dwarf planet Sedna (~1000 km.) the inclination is about 12 degrees.

    Sedna is in the lower part of the graphic above. In the view shown it’s not possible to see the relative inclinations.

  4. oldbrew says:

    The test of being ‘in the solar system’ could be a perihelion inside the limit of the heliosphere.
    The termination shock is somewhere beyond 75 AU according to Voyager data.

    No perihelion further from the Sun than Sedna (76 AU) here [except 2012 VP113 at ~80 AU].

    Another version of the same story:

  5. Richard Mallett says:

    Presumably the so called Planet 9 should be called a dwarf planet as it has also (like Pluto) not cleared its neighbourhood of other KBOs / TNOs.

  6. Graeme No.3 says:

    We will know its definite status when the Guardian claims that it is caused by Climate Change.

  7. oldbrew says:

    Richard M: Planet 9 hasn’t been found yet, so who can say what its neighbourhood looks like? If it exists at all of course.

  8. E.M.Smith says:

    The article says it is a KBO, so it cannot be a planet (due to their broken deffinition with clearing required…)

    Broken as it required an exception be added so Trojan asteroids wouldn’t make Jupiter be kicked out… broken since it means Earth wasn’t a planet until some point in the final crater forming process of 4.5 B years ago, that is ill defined… broken as a cometary breakup in your orbit can scatter debris and make you not a planet… for a while… Oh, and since the moon never goes retrograde in our mutual solar orbit, we need to either be a binary planet, or not a planet as we have not cleared our orbit…, oh and…

    They ought to have just defined a self rounding radius (say 1000 km) and orbiting the sun and moved on. Yeah, we’d have about 2 dozen planets, but I’m ok with that… (I.e just drop the word “dwarf” and they all go in the planet pile)

  9. […] Source: Scientists find more evidence of a ninth planet in our solar system  […]

  10. Geoff Sharp says:

    If Planet 9 existed with the suggested mass as outlined, there would be a huge effect on the path of the Sun about the SSB. The path of the Sun corresponds to the position of the outer 4 planets…end of story.

  11. Sparks says:

    This is bullshit on overdrive, there is no ninth planet, this speculation is the result of Uranus and Neptunes orbital parameters not conforming to belief…

  12. oldbrew says:

    The hardest one to explain is probably Sedna, which has a diameter of 1000 km. but never gets closer than 76 AU to the Sun, about 2.5 times further out than Neptune and near the limit of the heliosphere.

    ‘its aphelion [is] estimated at 937 AU (31 times Neptune’s distance), making it one of the most distant known objects in the Solar System other than long-period comets.’

    It’s unlikely its orbit can be influenced by the known major planets at such distances, so what forces are at work?

    Sedna (red), Jupiter (orange), Saturn (yellow), Uranus (green), Neptune (blue), and Pluto (purple)

  13. oldbrew says:

    The plot thickens: Researcher links mass extinctions to ‘Planet X’

    ‘Periodic mass extinctions on Earth, as indicated in the global fossil record, could be linked to a suspected ninth planet, according to research published by a faculty member of the University of Arkansas Department of Mathematical Sciences.

    Daniel Whitmire, a retired professor of astrophysics now working as a math instructor, published findings in the January issue of Monthly Notices of the Royal Astronomical Society that the as yet undiscovered “Planet X” triggers comet showers linked to mass extinctions on Earth at intervals of approximately 27 million years.’

  14. Bloke down the pub says:

    Planet nine or planet X
    Shouldn’t that be Planet IX?

    [reply] it was letter ‘X’

  15. p.g.sharrow says:

    It would appear that the ugly head of Immanual Velikovsky “War of the worlds” rears again.
    All the “educated” know that this is impossible. The Solar System is a well ordered machine.

    Of course, The Earth-Luna pair, The Neptune-Pluto group, The Uranus system, The Asteroid belts and Venus all give hints that some kind of large disrupter is out there and periodically swings through the inter-solar system causing events large and small…pg

  16. Oswald Thake says:

    I recall a book called ‘Nemesis’ by the son of Louis Alvarez which postulated a massive object out in the Oort cloud which caused periodic bombardments of the inner planet every 26 million years or so. He called it ‘Nemesis,’ hence the title of his book. Mr. Alvarez Jnr. was no slouch as a scientist, and his father won a Nobel Prize in Physics, so his theory more than deserves serious consideration, I think.

  17. oldbrew says:

    It’s not obvious why there would be a link between a distant planet with an estimated orbit period of about 20000 years, and repeating meteor showers every 20-odd million years.

    Something else would probably have to be involved as well.

    NB Apologies for delayed moderation – some extra comments now appear.

  18. J Martin says:

    Could Sedna be orbiting both the sun and the suns putative binary brown dwarf ?

  19. oldbrew says:

    Sedna’s orbit period is supposed to be over 11,000 years and nobody knows what’s at the ‘far end’.
    When it was spotted it was quite near perihelion (within a few AU) and it still is, in relative terms.

  20. oldbrew says:

    In an interview with the MailOnline, Brown pointed out that the Planet Nine he is looking for most likely isn’t the Planet X Whitmire and Matese hopes it is.

    “Whitmire has been speculating for decades about a very distant very massive planet pushing comets around. It has to have an orbital period of something like 27 million years,” said Brown. “While that idea may or may not make sense, it definitely has nothing to do with Planet Nine, which is much closer to the sun and thus ‘only’ takes 15,000 years to go around.”

    “The evidence for Planet Nine says nothing about whether or not there is a more distant Planet X.”

    That’s cleared that one up at least.

  21. Wayne Job says:

    The Sumarians in their writings say that planet X has an orbital period of 30,000 years and the last time it was close was at the time of the great flood. That would mean it is still outward bound and a long way from us. Very difficult to find.

  22. oldbrew says:

    Planet X and Planet Nine are unrelated ideas, as Mike Brown pointed out (see quote above).

    Visualising the distance to an imaginary Planet Nine…

    Jupiter is near the ball park but Planet Nine is a 5 hour hike.

  23. oldbrew says:

    Scholz’s Star: Binary System Passed through Outer Oort Cloud 70,000 Years Ago

    ‘No other star is known to have ever approached the Solar System this close – about 5 times closer than the current closest star, Proxima Centauri.’

    ‘Seen from our Solar System, Scholz’s Star barely moves across the across the sky. In fact careful radial velocity measurements (based on observations of the Doppler shift of emission lines in the star’s spectrum) indicate that the star is rapidly moving almost directly away from the Solar System.’

  24. oldbrew says:

    Here’s another POV.

    ‘…astronomers now agree that most stars are likely part of a binary or multiple star system. Dr. Richard A. Muller, professor of physics at UC Berkeley and research physicist at Lawrence Berkeley National Laboratory, is an early proponent of a companion star to our sun; he prefers a 26 million year orbit period. Cruttenden uses 24,000 years and says the change in angular direction can be seen in the precession of the equinox.’

    Read more at:

  25. oldbrew says:

    ‘Planet Nine is fact or theoretical myth, Astronomers are in clash’

    ‘Researchers believe that the new planet gravitationally dominates a chunk of space that is larger than any of the rest of the planets in the Solar System. This may be why a series of disturbances in the Kuiper Belt cannot be explained in the absence of a hidden planet.’

  26. oldbrew says:

    Another Planet 9 theory rolls off the production line.

    ‘Planet Nine might be an exoplanet stolen by the sun’

  27. oldbrew says:

    A more detailed version than some of the other reports.

    Quote: Several weeks back, those models got a big boost when Michele Bannister of the University of Victoria, Canada, revealed yet another Kuiper belt object on the same funky orbit as Planet nine’s original flock of six. “Our biggest worry was that the next set of objects we discover are going to destroy the pattern—that our brains had somehow tricked us,” Batygin said. “Instead, the first new object is exactly where our models say it should be. It basically falls on the mean.”

    OTOH it may also depend on where you look 😉

  28. oldbrew says:

    Astrophysicists at the University of Bern have modelled the evolution of the putative planet in the outer solar system.

  29. oldbrew says:

    Saturn spacecraft not affected by hypothetical Planet 9

    ‘”Although we’d love it if Cassini could help detect a new planet in the solar system, we do not see any perturbations in our orbit that we cannot explain with our current models,” said Earl Maize, Cassini project manager at JPL.

    Read more at:

  30. oldbrew says:

    Abstract: The effect of a trans-Plutonian planet on Halley’s comet

    An orbit and mass for a hypothetical trans-Plutonian planet is determined which reduces the residuals in the time of perihelion passage of Halley’s comet at the seven apparitions from 1910 to 1456 by 93%. The effect of this hypothetical planet on the major planets is briefly discussed, and it is shown that the residuals of two similar periodic comets, Olbers and Pons-Brooks, are also improved.

    Publications of the Astronomical Society of the Pacific © 1972 The University of Chicago Press

  31. oldbrew says:

    ‘Are we closer to finding a mystery world in our solar system? Scientists narrow down the location for Planet Nine’

    Quote: ‘researchers suggest the ninth planet may be toward the constellation of Cetus, in a small area of the sky that makes up just 20 degrees in radius.’

  32. oldbrew says:

    Planet Nine: A world that shouldn’t exist — Harvard-Smithsonian Center for Astrophysics

    Earlier this year scientists presented evidence for Planet Nine, a Neptune-mass planet in an elliptical orbit 10 times farther from our Sun than Pluto. Since then theorists have puzzled over how this planet could end up in such a distant orbit. New research examines a number of scenarios and finds that most of them have low probabilities. Therefore, the presence of Planet Nine remains a bit of a mystery.