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‘Goblin’ world found orbiting at the edges of the Solar System
- SideburnsOfDoom 8y agohttps://en.wikipedia.org/wiki/2015_TG387 https://en.wikipedia.org/wiki/2015_TG387 A short article, but in some ways more details. And some links
- __exit__ 8y agoThank you. So many new terms there: sednoids, Oort clouds...
- SideburnsOfDoom 8y ago"Sednoid" is a new term to me too, though clearly it means "an object like e.g. Sedna". https://en.wikipedia.org/wiki/90377_Sedna https://en.wikipedia.org/wiki/90377_Sedna Kuiper belt and Oort cloud are well-known decades-old terms https://en.wikipedia.org/wiki/Kuiper_belt https://en.wikipedia.org/wiki/Kuiper_belt https://en.wikipedia.org/wiki/Oort_cloud https://en.wikipedia.org/wiki/Oort_cloud
- __exit__ 8y agoFirst thing in my mind when reading "sednoid" was "mathematics!". As for the rest of the terms, they are new to me due to my non-familiarity with cosmology in general.
- swarnie_ 8y agoSlowly we're getting closer to proving another planet is out there. I do like it when nutters spewing out 100's of mad theories a month get one correct, in this case its the existence of Nibiru.
- rrmm 8y agoThe fun thing is that Planet X/Nibiru/Nemesis are basically crazy talk (but different from each other), and Planet IX is quite possibly true, but also distinct from the foregoing. But they are all synonymous in internet conspiracy land, (and in their eyes, corroborate each other's existence).
- swarnie_ 8y agoMy understanding is the term "Planet X" came about while we still called Pluto the 9th planet making Planet IX and X the same theory. Maybe i'm way off here, the government mind control satellites seem to have got to my reviewers.
- rrmm 8y agoThe paper this article refers to actually refers to 'Planet X' as the theorized large planet in its section on orbital stability models. I think the planet X moniker originally meant 'x' as unknown (it was coined during the search that found Pluto). Nowadays, it has been used to refer to several distinct theories including Planet IX. I dunno when exactly the X got re-interpreted. What I do know is WE'RE DOOOOMED! (according to the internet).
- etatoby 8y agoAs soon as the Annunaki come to take what's theirs, yes we are. (j/k)
- XzetaU8 8y agoPlease watch this [1] it will probably help you understand why the Nibiru/PlanetX claims are nothing but a fairy tale. [1]https://www.youtube.com/watch?v=fepV7dqh5vg https://www.youtube.com/watch?v=fepV7dqh5vg
- Simon_says 8y agoWas anybody here in danger of thinking that?
- Tor3 8y agoWhy 'Goblin', though? There's no explanation in the article, nor on the wikipedia page, and I can't imagine an explanation by myself.
- KineticLensman 8y ago> Named 2015 TG387 and nicknamed The Goblin I also wondered if it was representative of a class of Goblin objects. I guess the discoverers just liked 'goblin' as a term for something that stays in the dark.
- theandrewbailey 8y agoFor some reason, I wondered if this object was made of cobalt (goblin ore).
- deadmetheny 8y agoI thought Goblinite was an ore of iron.
- billysielu 8y agoIt's because the goblins live there, duh :)
- deleted 8y ago[deleted]
- 0xdeadbeefbabe 8y agoGollems probably live there too.
- deleted 8y ago[deleted]
- insickness 8y agoBecause it's small and exists in darkness in the outer realms. Also, it's just great marketing. Who the hell wouldn't want to read about a goblin planet? Made me click on the link.
- wycy 8y agoI gather from this article that its orbital radius varies between 65 AU and 2300 AU, which is an extremely eccentric ellipse. I wonder if that high eccentricity would disqualify it from "planet" status. Most other bodies considered "planets" are far closer to circular. It's also unclear to me if the Goblin orbits in the usual planetary plane.
- pas 8y agoProbably the simple fact that it does not clear its orbit disqualifies it from planet status. And it's probably too small to be in hydrostatic equilibrium (not enough self-gravity to force it to a roundish shape).
- schindlabua 8y agoOut of interest: I looked up "Hydrostatic equilibrium" and it says "[thing is in equilibrium] when the flow velocity at each point is constant over time". How exactly does that statement relate to what you said?
- scardine 8y agoFrom the wikipedia article about Ceres[1]: > A proposal before the International Astronomical Union for the definition of a planet would have defined a planet as "a celestial body that (a) has sufficient mass for its self-gravity to overcome rigid-body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (b) is in orbit around a star, and is neither a star nor a satellite of a planet"[2]. [1] https://en.wikipedia.org/wiki/Ceres_(dwarf_planet) https://en.wikipedia.org/wiki/Ceres_(dwarf_planet) [2] https://www.webcitation.org/62D6DNhLH?url=http://www.iau.org/iau0601.424.0.html https://www.webcitation.org/62D6DNhLH?url=http://www.iau.org...
- grigjd3 8y agoMost objects in space have some amount of spin to them. That is particles throughout a body, each with a velocity that may be changing, but the change in velocity with position is smooth, or the object would be ripping itself apart. This means the object has flow. A noticeably misshapen object will not have relatively constant speed and angular direction as a function of latitude and radius. However, objects that gravity rounds out do have this feature (to within an approximation, there is still weather). Thus the term hydrostatic equilibrium. The reason we don't just say "circular" is that this does not include oblate objects, which result from higher spin.
- rrmm 8y agoThe pre-print pdf is https://arxiv.org/pdf/1810.00013.pdf https://arxiv.org/pdf/1810.00013.pdf Inclination of 11.669 degrees The diameter listed in the paper is 300km assuming a moderate albedo of 15%. The paper suggested this object provides more evidence of the existence of Planet X/IX hypotheses of the authors (Trujillo/Shepard/et.al.) and Brown/Batygin.
- interfixus 8y agoSo, we can detect - see, dammit - something perhaps only 300km across at twice the distance to Pluto, and by reflected light alone. Every now and again, my intuition breaks utterly down.
- etatoby 8y agoAnd through the atmosphere, no less. (The telescope used is in Hawaii)
- okket 8y agoAdaptive optics [0] takes care of atmospheric distortions. Combined with the huge telescopes that are possible on earth and impossible to ferry to space in the foreseeable future, advancements in sensors and data processing, which is also much, much easier on earth and at best possible with constraints / a long delay in space, I think earth based telescopes are still the future. Special cases like the infrared spectrum (JWT) exist. But the delays show how extremely difficult space based observation is. [0] https://en.wikipedia.org/wiki/Adaptive_optics https://en.wikipedia.org/wiki/Adaptive_optics [Edit: wrong link]
- kroltan 8y ago"Active optics is not to be confused with adaptive optics, which operates at a shorter timescale and corrects atmospheric distortions." ~ "Active optics", Wikipedia https://en.wikipedia.org/wiki/Adaptive_optics https://en.wikipedia.org/wiki/Adaptive_optics
- pard68 8y ago> popularly known as Planet Nine Poor Pluto...
- zumu 8y agoIt used to be popularly called Planet X. I've heard it to referred to as Planet Nine
- BuckRogers 8y agoYeah, I can't get Planet X out of my mind. It sounds better anyway, with a little more mystery.
- tibbon 8y agoWhat is the far out giant planet it mentions?
- autocorr 8y agoThey don't explain it in detail, but the reason it's consistent with Planet IX [1] is its orbit has specific properties that require a near pass with a large body in the outer solar system (basically the definition of Planet XI). That seems like it may be easy to do by other means, but if you've played Kerbal Space Program you know how difficult it can be to change all six orbital elements in the way you want to. For example, a close pass to Jupiter could launch something extremely far our, but it would not change it's perihelion or closest approach to the Sun. Like a Homann transfer, going to a larger orbit requires at least two "kicks": one to kick it into an ellipse and a second at the outer point. Planet XI would give the kick at a far distance to get many of these curious Trans-Neptunian Objects out to crazy perihelion distances like 65 au. There's also a specific effect to the inclination and argument of perihelion, but I don't understand how these work as well. The amount of sky we have to look for Planet IX is enormous (and given how faint it is likely to be), and the evidence so consists of about ten of these TNOs with these orbits (not many, but it's very hard to make these orbits). But there are potentially hundreds of bodies with orbits like these waiting to be found by a the soon to be constructed LSST, which is an 8 meter telescope that will survey its entire sky every 3 days. With many more of these orbits to predict from, we may really narrow down the search space to look for it, and ultimately test its existence. [1] Predicted by Konstantin Batygin and Mike Brown, the latter of which played a big part in helping to disqualify Pluto as a planet by discovering Eris. I know from a lunch-talk that he greatly relishs the thought of both demoting the former Planet XI and predicting the new one.
- Kapow 8y agoI think you have some XIs that should be IXs.
- wmeredith 8y agoAnd an it’s that should be an its. This was hard to read.
- sandworm101 8y ago>> There's also a specific effect to the inclination and argument of perihelion. To get a significant inclination (ie away from the low inclinations of the inner planets) and a drop in the perihelion (ie highly oval rather than the round orbits of the inner planets) you need a close pass of a large body. As the little think comes close to the big thing it is thrown randomly, away from the nicely round orbits of most things in the early solar system. So if you find a body with those two features, you know it passed close to something big somewhere our near the highest part of its orbit. That is the evidence of a large object out beyond pluto.
- walrus01 8y agoThis is now the third Sednoid discovered. https://en.m.wikipedia.org/wiki/Sednoid https://en.m.wikipedia.org/wiki/Sednoid