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posted by martyb on Monday June 26 2017, @12:06AM   Printer-friendly
from the warp-and...weft? dept.

Astronomers are inferring the existence of a "Planet Ten" (or actually the true "Planet Nine"?), a Mars-sized body in the Kuiper Belt, several times closer to the Sun than where the hypothetical Neptune-like Planet Nine is expected to be:

An unknown, unseen "planetary mass object" may lurk in the outer reaches of our solar system, according to new research on the orbits of minor planets to be published in the Astronomical Journal. This object would be different from — and much closer than — the so-called Planet Nine, a planet whose existence yet awaits confirmation.

In the paper, Kat Volk and Renu Malhotra of the University of Arizona's Lunar and Planetary Laboratory, or LPL, present compelling evidence of a yet-to-be-discovered planetary body with a mass somewhere between that of Mars and Earth. The mysterious mass, the authors show, has given away its presence — for now — only by controlling the orbital planes of a population of space rocks known as Kuiper Belt objects, or KBOs, in the icy outskirts of the solar system.

[...] According to the calculations, an object with the mass of Mars orbiting roughly 60 AU from the sun on an orbit tilted by about eight degrees (to the average plane of the known planets) has sufficient gravitational influence to warp the orbital plane of the distant KBOs within about 10 AU to either side.

Also at New Scientist.

The curiously warped mean plane of the Kuiper belt

We estimate this deviation from the expected mean plane to be statistically significant at the ∼97−99% confidence level. We discuss several possible explanations for this deviation, including the possibility that a relatively close-in (a≲100~au), unseen small planetary-mass object in the outer solar system is responsible for the warping.


Original Submission

 
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  • (Score: 2) by Runaway1956 on Monday June 26 2017, @04:21AM (13 children)

    by Runaway1956 (2926) Subscriber Badge on Monday June 26 2017, @04:21AM (#531110) Journal

    Yep - wobble and occultation. Now, some folk think that there is an invisible planet in our own backyard. So, how hard is it to calculate the most likely places for that planet to be, then watch for it to occlude the stars behind it? I mean, that planet can't just be anywhere, can it? If it's creating wobbles in the orbits of the known planets, then those wobbles have to indicate (to some degree of accuracy, anywah) where that planet would be in it's orbit. I think we can presume that the planet is pretty close to the ecliptic plane. Pluto is 17 degrees off of the ecliptic, Mercury only 7 degrees off - all the rest are pretty much right on it.

    You might argue that there are more important things to which me should devote out telescope time. I would argue right back that confirming the planetary population of our own system is far more pertinent than anything that might be light years away. Assuming that we ever do colonize and settle our own solar system, that mysterious planet may prove pretty damned important. There might be life on it, or there may be resources that we need. For instance, consider our preoccupation with stealth. That planet is pretty damned stealthy, isn't it? It's probably covered in stealthite, and all we need do is go there, mine it, melt it, and make our next generation stealth fighters and ships with it.

    Alright, so that last is sarcasm. Sue me.

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  • (Score: 2) by KGIII on Monday June 26 2017, @04:42AM (11 children)

    by KGIII (5261) on Monday June 26 2017, @04:42AM (#531123) Journal

    How hard is it? Pretty hard. Also, space is fucking huge.

    --
    "So long and thanks for all the fish."
    • (Score: 2, Interesting) by Runaway1956 on Monday June 26 2017, @04:48AM (10 children)

      by Runaway1956 (2926) Subscriber Badge on Monday June 26 2017, @04:48AM (#531124) Journal

      Yes, of course space is huge. But, we are only concerned with the ecliptic plane, and only a relatively small part of that. And, did I mention that there's a pretty good chance that there are seas of unobtanium hidden under the stealthite crust? ;^)

      • (Score: 2) by Weasley on Monday June 26 2017, @05:26AM (4 children)

        by Weasley (6421) on Monday June 26 2017, @05:26AM (#531140)

        Are you trolling here? No, it's not a small portion of the sky. It's a very large portion of the sky. There are other factors too. Objects that far out move much more slowly around the sun. You have to get two or three pictures of the object in different positions to determine if you're looking at a moving object. For asteroids you can gather these images in a single night to determine something is there. For TNOs you may be looking at multiple nights. Furthermore, objects that far out are extremely dim. You can take longer exposures to pick up dimmer and dimmer objects, but the longer you expose an image, the more likely the object in question is going to move far enough in the sky so that the object begins exposing a different pixel on your camera, and thus not standout against the noise. That means you need an extremely large aperture scope to collect enough light to expose your pixels in a reasonable amount of time. You need extremely specialized telescopes to efficiently perform this work; there are only so many out there suited for it. All this is assuming the object is even bright enough to be detected by them.

        • (Score: 1, Troll) by Runaway1956 on Monday June 26 2017, @07:55AM (3 children)

          by Runaway1956 (2926) Subscriber Badge on Monday June 26 2017, @07:55AM (#531181) Journal

          Trolling? Please, look at the title I chose for my post. "Amusing perspective". Come on man, isn't it obvious that I'm not really serious here? I'm amused.

          For a comparison, let's imagine the person who can't find his own possessions in his own bedroom - but he pretends to know how to find his way around every city on the globe.

          • (Score: 0) by Anonymous Coward on Monday June 26 2017, @08:46AM (1 child)

            by Anonymous Coward on Monday June 26 2017, @08:46AM (#531205)

            Come on man, isn't it obvious that I'm not really serious here? I'm amused.

            Or, to repeat, for extra redundancy: "Not serious, amused, ignorant, and trolling."

            • (Score: 0) by Anonymous Coward on Monday June 26 2017, @09:57AM

              by Anonymous Coward on Monday June 26 2017, @09:57AM (#531232)

              WE are not amused.

          • (Score: 3, Insightful) by Grishnakh on Monday June 26 2017, @03:20PM

            by Grishnakh (2831) on Monday June 26 2017, @03:20PM (#531350)

            Your analogy is silly. Here's a better analogy:

            Personally, I live pretty close to a creek and a river (each less than a half-mile away as the crow flies), and about an hour's drive from a very large metro area. I also live close to some various little towns, rural roads, etc. Which do I know more about: places much close to me, such as someone's random trailer home in the woods, or some sunken fishing boat at the bottom of the river? Or how to get around that metro area that's over an hour away, and various points of interest there? The latter. There's nothing important to me about some old junk lying at the bottom of the river, or geographic features of the river bed, or some crappy little town 15 minutes away that has one shitty little grocery store and a gas station and maybe a cigarette shop, or various peoples' homes in the area scattered all over different rural roads. But going to the city, visiting cultural attractions there, getting around there, etc. is far more important to me, so that's where I concentrate my attention.

      • (Score: 3, Interesting) by c0lo on Monday June 26 2017, @05:37AM (2 children)

        by c0lo (156) Subscriber Badge on Monday June 26 2017, @05:37AM (#531143) Journal

        Yes, of course space is huge. But, we are only concerned with the ecliptic plane, and only a relatively small part of that.

        High school exercises:

        ---
        Exercise A.
        1. compute the area of a sphere with a radius of 60AU
        2. compute the area of a disc with the radius equal with the Earth one placed at a distance of 59 AU from the observer
        3. divide the result at point one with the value at point 2 and see what are the chances of that disc be in the direction of sight of a random observer. Communicate the result.

        ---
        Exercise B. Note that exercise A discarded (at point 1) the information about the area swiped by +/-8degrees range around the ecliptic plane, in which we guessed the planet may be. Correct it [wikipedia.org] and recompute steps 2 and 3.

        If you get the answer to Exercise B, you'll understand why is so freaking hard to spot it without any extra information.

        ---
        Exercise C. Compute the period of a planet orbiting the Sun at 60 AU. How long will you need to observe the same region of space to witness a direct occultation of a star behind it.

        Exercise B.
        The area of a spherical zone at 59AU and spanning +/-8 degrees around ecliptic is 2.3857e+18sqkm.
        The area of the apparent disc of an Earth size planet is 1.2752e+8.
        Pick a direction of sight at random - the probability of that direction to intersect an Earth-size-at-59AU disc is 5.345e-11.
        Comparison:
        a. the probability to win a 6/49 lottery Jackpot is 7.15e-8.
        b. The probability to be killed by a lightning is (currently) approx 1/300000=3.33e-6)
        Exercise C
        Third Kepler Law with the distance of 60AU and mass equal with Earth gives around 465 years
        --
        https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
        • (Score: 0) by Anonymous Coward on Monday June 26 2017, @06:09AM (1 child)

          by Anonymous Coward on Monday June 26 2017, @06:09AM (#531150)
          Not to mention that the body in question will be very faint. The Hubble Space Telescope can resolve an object at magnitude 31.5, but that would require an incredibly long exposure time. This might be enough to be able to see a Neptune-size planet at 100 AU, but you would definitely need to know exactly where to point Hubble because your exposure time will be damned long.
          • (Score: 2) by takyon on Monday June 26 2017, @09:21AM

            by takyon (881) <takyonNO@SPAMsoylentnews.org> on Monday June 26 2017, @09:21AM (#531218) Journal

            Planet Nine is believed to be somewhere from 200 to 1200 AU away, and smaller than Neptune (I would assume this would be exasperated by a lower temperature which shrinks gas planets). So the conditions for imaging it are probably worse than what you listed. But there is some good news [wikipedia.org]:

            The Hubble telescope can detect objects as faint as 31st magnitude, and the James Webb Space Telescope (operating in the infrared spectrum) is expected to have an absolute magnitude limit of 34th magnitude.

            --
            [SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
      • (Score: 2) by KGIII on Monday June 26 2017, @08:20AM

        by KGIII (5261) on Monday June 26 2017, @08:20AM (#531195) Journal

        LOL Space is huge. Like, bigger than you can actually picture in your head. The number of units has no meaning to you - or me. It's that big, and that just that far away. It keeps getting bigger, too.

        --
        "So long and thanks for all the fish."
      • (Score: 0) by Anonymous Coward on Monday June 26 2017, @10:22AM

        by Anonymous Coward on Monday June 26 2017, @10:22AM (#531241)

        And how are you going to know what wobble is caused by an exoplanet and what is going to be caused by "Planet Ten"?

        More importantly, a single wobble in a star isn't enough for them to verify "YES! THAT WAS A PLANET!" They see a wobble and they go "Oh hey, let's keep watching that to see if it happens again, and how often it does."

        With Planet Ten, odds are after it wobbles a single star, it's not going to wobble that star ever again as it continues it's revolution around the sun. Unless you want to sit around and wait a few hundred to a few thousand years of course.

  • (Score: 2) by Grishnakh on Monday June 26 2017, @03:12PM

    by Grishnakh (2831) on Monday June 26 2017, @03:12PM (#531346)

    If there is a "Planet X" out there in the Kuiper Belt, it'd be utterly useless for human habitation: it's too cold and too far away. That's why we don't bother expending that many resources looking for stuff out there.

    If you want to do mining in the Solar System, there's plenty of other places far closer to start with, namely the Moon and earth-crossing asteroids. After that, we have Mars, the whole Asteroid Belt, and Mercury, and after that the gazillion moons (and moonlets and "Trojans" and other various little rocks) orbiting Saturn and Jupiter and the ice giants after them. It'll be a LONG time before we use up that stuff and need to start looking at the Kuiper Belt for resources; we haven't gotten started exploiting the resources we have right here in our own neighborhood.