[HN Gopher] A 1980s space telescope may have seen planet nine
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A 1980s space telescope may have seen planet nine
Author : starwind
Score : 64 points
Date : 2021-11-16 20:52 UTC (2 hours ago)
(HTM) web link (gizmodo.com)
(TXT) w3m dump (gizmodo.com)
| starwind wrote:
| Relevant part:
|
| For the recent work, [Michael] Rowan-Robinson redid his search
| from nearly 40 years ago and found three points in the data from
| late summer 1983 that indicate some object moving across the sky.
| The data sources sit low on the galactic plane, though, meaning
| that the satellite was taking the data through plenty of dusty,
| cloudy material that can emit infrared light. In other words, the
| work is something of a long shot. And Rowan-Robinson is well
| aware of that. "Given the poor quality of the IRAS detections, at
| the very limit of the survey, and in a very difficult part of the
| sky for far infrared detections, the probability of the candidate
| being real is not overwhelming," he wrote in his paper.
| _Microft wrote:
| Isn't that bigger news than it sounds at first? Part of the
| problem of finding planet nine must be knowing where it
| currently is on its orbit. A few possible observations should
| help to narrow down the space in which to look for it by a lot
| (rather: would make it almost clear where it currently is).
| Maybe JWST could be of help with testing the hypothesis that
| these early infrared observations of a moving object were of
| planet nine - once it has finally and savely launched and begun
| its operations?
| xook wrote:
| Would have commented this same thing. It should be a matter
| of translating the coordinates into a search pattern to look
| at with JWST.
| api wrote:
| If they don't name it Yuggoth I will be disappointed.
|
| https://lovecraft.fandom.com/wiki/Yuggoth
| Hemospectrum wrote:
| There's all kinds of silly names they could borrow from stories
| hypothesizing its existence. Nemesis, Nibiru, Vulcan, and
| Planet X, just for starters. But in all likelihood it will end
| up as something much more anodyne.
| BitwiseFool wrote:
| I think the IAU will only accept names from Mythology.
| gre wrote:
| Here's a youtube video by Anton Petrov describing the paper
| https://www.youtube.com/watch?v=ZSyAO4fGZOE
| ziddoap wrote:
| He's always quick on these, and always with quality videos.
|
| Anyone with an interest in space who has not watched any of
| Anton's videos are seriously missing out.
| Diederich wrote:
| So say we all.
|
| I watch all of his videos and it's always an interesting,
| learning experience.
| lutorm wrote:
| Lol, Hubble is a "1980s space telescope". It was launched in
| April 1990....
| lp0_on_fire wrote:
| Amazing how they could design and built such a device in four
| months...
|
| /s
| HenryKissinger wrote:
| If Planet 9 contains rare earth metals, mining and manufacturing
| facilities could be built there. This should help alleviate the
| chip shortage.
| echelon wrote:
| We have plenty of rare earths here on our homeworld. If we run
| out (which we won't), we'll scavenge before we build the
| trillions of dollars of infrastructure necessary to mine the
| solar system.
| guerrilla wrote:
| Rare Earth metals aren't actually that rare. We even have a lot
| of big mines that are closed right now because its not
| profitable enough yet and many other sites enrirely
| undeveloped.
| gameswithgo wrote:
| Is this performance art? Do some napkin math on the quantities
| of fuel alone required to do this.
| kjs3 wrote:
| Or we could, you know, build mining and manufacturing
| facilities on a planet that's, say a couple of AU away, instead
| of a couple of hundred AU. There's reasons we've done neither.
| nsf39k wrote:
| The technology and infrastructure needed to reach Planet 9,
| build a mining outpost, then transport everything back at a
| _profitable_ cost is likely decades if not centuries away.
| That's not counting the fact that Planet 9 is so far away that
| getting there with current technology is a lengthy affair in
| itself (the New Horizons probe wouldn't even be halfway to a
| theoretical Planet 9, and it's been flying for over 15 years!)
|
| Not saying I don't want this to happen - I would love nothing
| more than to have humanity push out into the solar system, but
| recycling or scavenging is infinitely more of an realistic
| option.
| pfdietz wrote:
| Rare earths are neither particularly rare, nor particularly
| likely to be unusually abundant on a Planet 9.
|
| However!
|
| A Mars or Earth-sized planet sufficiently far out in the solar
| system might be sufficiently cool to be able to retain helium
| in its atmosphere, without being a gas giant planet. If so, it
| might conceivably be the best place in the solar system to
| obtain 3He, an isotope that has considerable attractiveness for
| use in fusion reactors. A D-3He fusion rocket might even
| provide a nice way of getting out there and back in a
| reasonable time.
| [deleted]
| WarOnPrivacy wrote:
| _The Vera Rubin Observatory in Chile is under construction and
| will image the entire sky every week using the largest digital
| camera ever built._
|
| Hopefully searches along the plane of the ecliptic won't be
| sabotaged by Starlink or other LEO satellites.
| tick_tock_tick wrote:
| Large facilities were never threatened by Starlink as they
| easily compensate the issue was amateur's and very small
| facilities.
| spacemark wrote:
| Not true at all, totally depends on the type of observation
| campaign. Plenty of big observatory projects are negatively
| impacted by the eternal march of "progress."
| tick_tock_tick wrote:
| > "progress."
|
| Do you really think Starlink is not a step forward? It is
| realistically the only path to get the whole world access
| to the internet.
| croddin wrote:
| If this object did exist, wouldn't it be classified as a dwarf
| planet since, like Pluto, with a highly elliptical orbit it would
| be difficult to clear it of other Kuiper belt objects?
| alex_young wrote:
| An object with multiple Earth masses could hardly be classified
| as a dwarf planet.
| vikingerik wrote:
| It very well could. Defining a planet as major or dwarf goes
| by its ability or inability to "clear the neighborhood", to
| control or remove objects of smaller mass in its orbital
| area.
|
| 225 AU is a long way, and the volume of space to clear goes
| up quadratically with distance; this object would have 50,000
| times more space to clear than does Earth. The orbital period
| also goes up with distance [edit, reply is right that it's
| the 3/2th power], so so does the time between interactions
| with any particular object.
|
| Multiply those together and you would have an object more
| than cubically (3.5th power) less effective than Earth at
| clearing its neighborhood over time, such that it may not
| have happened in the lifetime of the solar system.
| lanna wrote:
| > The orbital period also goes up quadratically with
| distance
|
| By Kepler's Third Law, isn't it proportional to the square
| root of the cube (3/2th power) of the distance?
| ithinkso wrote:
| It's on a plane. Circumference goes up lineary
| vikingerik wrote:
| It's undefined whether "clearing the neighborhood"
| involves the spheroid at that distance or just the plane.
| It hasn't come up, since all eight known major planets do
| satisfy the three-dimensional criterion. We'd probably
| revise or clarify the definition if we discovered an
| object that cleared its plane but not its volume.
| kbelder wrote:
| "A "dwarf planet" is a celestial body that (a) is in orbit
| around the Sun, (b) has sufficient mass for its self-gravity
| to overcome rigid body forces so that it assumes a
| hydrostatic equilibrium (nearly round) shape, (c) has not
| cleared the neighbourhood around its orbit, and (d) is not a
| satellite."
|
| According the the wrong-headed AIU definition. So, yes,
| _Jupiter_ could be a dwarf planet, if it hasn't cleared it's
| orbital neighborhood for some reason.
| skykooler wrote:
| I think the criteria are more along the lines of
| "gravitationally dominate its orbit", which due to the
| perturbations of KBOs this object would do. Otherwise,
| basically all planets would be demoted (e.g. Neptune has not
| cleared its orbit because Pluto is there, Jupiter hasn't
| because of the Trojans, etc.)
| slyall wrote:
| I asked Mike Brown this on twitter earlier this year and he
| said it will have cleared out it's orbit so that won't be a
| problem.
|
| " definitely clears! "
|
| https://twitter.com/plutokiller/status/1433802812945625095
| odyssey7 wrote:
| The sufficient-but-not-necessary conditions for identifying a
| planet are called into question as a workable definition once
| more.
|
| We've duck-typed the solar system, I guess.
| readthenotes1 wrote:
| "Scientists who search for Planet Nine estimate that its mass
| is several times bigger than Earth's... "
|
| So no. It won't be a dwarf planet.
| mgaunard wrote:
| There's always something weird beyond Uranus.
| worewood wrote:
| That subtitle was in no way accidental.
| bshipp wrote:
| I might physically appear be middle-aged but the 12-year-old in
| me snickered loudly.
| ptidhomme wrote:
| Should have been Neptune right.
| nashashmi wrote:
| Honest question:
|
| Can't the oddity of planet orbits also be explained by a sun in
| motion causing the orbits to be a little dragged shape? The
| direction of drag is probably the ghost planet 9?
| smlacy wrote:
| Am I the only one who's mildly annoyed by the 9th planet being
| referred to as Planet X?
|
| Seems like "Planet Ix" (same pronunciation!) would have been a
| better name?
| cheaprentalyeti wrote:
| I just bent space from Ix. Many new machines there.
| kjs3 wrote:
| The theory was proposed and it was anointed 'Planet X' when
| Pluto was the 9th planet, with X as the Roman numeral for 10.
| Now it's a play on 'X' being something unknown. Nothing to get
| annoyed about.
| lainga wrote:
| The designation was not a Roman numeral but Lowell's
| designation for "unknown". It would have been the 9th planet if
| discovered, at the time Lowell coined it, anyway
| usefulcat wrote:
| Pluto was still considered a planet in the eighties, so at
| that point an additional planet (if discovered) would have
| been the 10th planet.
| Asraelite wrote:
| Pluto was discovered in 1930. The term was coined decades
| before that.
| [deleted]
| rich_sasha wrote:
| I think it's a semi-deliberate pun. It was Planet 10 when
| people started looking for it. Then it would be "Planet 9",
| which is confusing. So they called it then "Planet X" as in
| 'ex', nerdily harking back to the good old days when Pluto was
| still a planet.
| tectonic wrote:
| Mike Brown recently wrote a summary of his and Konstantin
| Batygin's paper 'The orbit of Planet Nine'. By looking at Kuiper
| belt objects (KBOs) whose orbits appear skewed by the invisible
| gravity of a possible Planet Nine, accounting for observation
| bias, and running a ton of simulations and MCMC, they concluded:
| if it exists, Planet Nine has a mass of 6.2 (+2.2/-1.3) Earth
| masses and a perihelion (closest approach to the Sun) of 300
| (+85/-60) AU. The median distance at aphelion is around 500 AU.
| Those are not small error bars, but they do constrain the search,
| and this proposed finding of 225+-15 AU and a mass of 3-5 ME
| could just ~barely~ fit.
|
| The summary: https://findplanetnine.blogspot.com/2021/08/the-
| orbit-of-pla...
|
| We've been covering this search in Orbital Index
| (https://orbitalindex.com), subscribe if you want updates.
| staticautomatic wrote:
| Perhaps a dumb question, but if we have some idea of where it
| was and its probable orbit back then, then why don't we have
| some idea of where it is now?
| tectonic wrote:
| Also, Mike Brown's free 'The Science of the Solar System'
| course on Coursera is excellent. Highly recommended.
| https://www.coursera.org/learn/solar-system
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(page generated 2021-11-16 23:00 UTC)