Researchers Find Evidence Of Distant Outer Planet |
Researchers Find Evidence Of Distant Outer Planet |
Jan 20 2016, 04:58 PM
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#1
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Member Group: Members Posts: 723 Joined: 13-June 04 Member No.: 82 |
Free to view paper:
Evidence for a Distant Giant Planet in the Solar System Konstantin Batygin and Michael E. Brown QUOTE Abstract Recent analyses have shown that distant orbits within the scattered disk population of the Kuiper Belt exhibit an unexpected clustering in their respective arguments of perihelion. While several hypotheses have been put forward to explain this alignment, to date, a theoretical model that can successfully account for the observations remains elusive. In this work we show that the orbits of distant Kuiper Belt objects (KBOs) cluster not only in argument of perihelion, but also in physical space. We demonstrate that the perihelion positions and orbital planes of the objects are tightly confined and that such a clustering has only a probability of 0.007% to be due to chance, thus requiring a dynamical origin. We find that the observed orbital alignment can be maintained by a distant eccentric planet with mass gsim10 m⊕ whose orbit lies in approximately the same plane as those of the distant KBOs, but whose perihelion is 180° away from the perihelia of the minor bodies. In addition to accounting for the observed orbital alignment, the existence of such a planet naturally explains the presence of high-perihelion Sedna-like objects, as well as the known collection of high semimajor axis objects with inclinations between 60° and 150° whose origin was previously unclear. Continued analysis of both distant and highly inclined outer solar system objects provides the opportunity for testing our hypothesis as well as further constraining the orbital elements and mass of the distant planet. QUOTE 6. SUMMARY To date, the distinctive orbital alignment observed within the scattered disk population of the Kuiper Belt remains largely unexplained. Accordingly, the primary purpose of this study has been to identify a physical mechanism that can generate and maintain the peculiar clustering of orbital elements in the remote outskirts of the solar system. Here, we have proposed that the process of resonant coupling with a distant, planetary mass companion can explain the available data, and have outlined an observational test that can validate or refute our hypothesis. We began our analysis with a re-examination of the available data. To this end, in addition to the previously known grouping of the arguments of perihelia (Trujillo & Sheppard 2014), we have identified ancillary clustering in the longitude of the ascending node of distant KBOs and showed that objects that are not actively scattering off of Neptune exhibit true orbital confinement in inertial space. The aim of subsequent calculations was then to establish whether gravitational perturbations arising from a yet-unidentified planetary-mass body that occupies an extended, but nevertheless bound, orbit can adequately explain the observational data. The likely range of orbital properties of the distant perturber was motivated by analytic considerations, originating within the framework of octupole-order secular theory. By constructing secular phase-space portraits of a strictly planar system, we demonstrated that a highly eccentric distant perturber can drive significant modulation of particle eccentricities and libration of apsidal lines such that the perturber's orbit continuously encloses interior KBOs. Intriguingly, numerical reconstruction of the projected phase-space portraits revealed that, in addition to secular interactions, resonant coupling may strongly affect the dynamical evolution of KBOs residing within the relevant range of orbital parameters. More specifically, direct N-body calculations have shown that grossly overlapped, apsidally anti-aligned orbits can be maintained at nearly Neptune-crossing eccentricities by a highly elliptical perturber, resulting in persistent near-colinearity of KBO perihelia. Having identified an illustrative set of orbital properties of the perturber in the planar case, we demonstrated that an inclined object with similar parameters can dynamically carve a population of particles that is confined both apsidally and nodally. Such sculpting leads to a family of orbits that is clustered in physical space, in agreement with the data. Although the model proposed herein is characterized by a multitude of quantities that are inherently degenerate with respect to one another, our calculations suggest that a perturber on an a' ~ 700 AU, e' ~ 0.6 orbit would have to be somewhat more massive (e.g., a factor of a few) than m' = 10 m⊕ to produce the desired effect. A unique prediction that arises within the context of our resonant coupling model is that the perturber allows for the existence of an additional population of high-perihelion KBOs that do not exhibit the same type of orbital clustering as the identified objects. Observational efforts aimed at discovering such objects, as well as directly detecting the distant perturber itself constitute the best path toward testing our hypothesis. So about the size of Neptune, if their hypothesis is correct. |
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Mar 26 2016, 03:11 PM
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#2
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Senior Member Group: Members Posts: 1669 Joined: 5-March 05 From: Boulder, CO Member No.: 184 |
Clever with consideration of resonances. It appears they are just about telling us where we can actually look.
-------------------- Steve [ my home page and planetary maps page ]
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Apr 10 2016, 06:51 PM
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#3
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Member Group: Members Posts: 684 Joined: 24-July 15 Member No.: 7619 |
Clever with consideration of resonances. It appears they are just about telling us where we can actually look. Well, plugging in some rough numbers, QUOTE "Planet Nine" "Sol" { Class "planet" Texture "neptune.jpg" Color [ 0.65 0.45 0.35 ] Radius 14000 # rough guess EllipticalOrbit { Period 15000 SemiMajorAxis 700 Eccentricity 0.6 Inclination 30 AscendingNode 90 ArgOfPerihelion 150 MeanAnomaly 0 Albedo 0.15 Epoch 2456800.5 } } somewhere along the red line Hmm, still have to tweak those parameters, that does generate a track which is similar to other published paths, but when you zoom out, Planet 9 is on the same side as Sedna. |
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Apr 11 2016, 03:25 PM
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Member Group: Members Posts: 127 Joined: 20-April 05 Member No.: 291 |
An author at Centauri-Dreams.org started the ball rolling on what kind of technology could be used for a theoretical mission to Planet 9. A probe moving at New Horizons 4-2.5 AU/year would need centuries to arrive - a 10 fold increase in velocity is going to be needed for a probe to arrive in a "reasonable" (20-30 year) time.
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Guest_Steve5304_* |
Apr 12 2016, 06:28 PM
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#5
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Guests |
An author at Centauri-Dreams.org started the ball rolling on what kind of technology could be used for a theoretical mission to Planet 9. A probe moving at New Horizons 4-2.5 AU/year would need centuries to arrive - a 10 fold increase in velocity is going to be needed for a probe to arrive in a "reasonable" (20-30 year) time. Absolute waste of time right now until these hypothetical engines make it feasible IMO, we might aswell shoot for other stars cause 600au is a fraction of the distance (albeit small). Money is better spent on researching telescopes that would be sensitive to view in a decent resolution. None of us would be alive if a probe took off today heading at Pioneer Speeds would take to long. For whatever reason NASA is not very interested or not funded enough to seriously pursue new propulsion. Other than Ion Drive & Gravity Assist, nothing has innovated since the 1960's. |
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Apr 12 2016, 11:40 PM
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#6
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Senior Member Group: Members Posts: 2530 Joined: 20-April 05 Member No.: 321 |
The lack of innovation has been discussed and largely rebutted here:
http://www.unmannedspaceflight.com/index.php?showtopic=7842 |
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Apr 13 2016, 11:18 AM
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#7
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Member Group: Members Posts: 127 Joined: 20-April 05 Member No.: 291 |
With the electric-ion engines we have now - isn't the issue just finding a powersource that we can pair up with it to provide thrust for the necessary length of time?
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