Mysterious Object Glimpsed Decades Ago Might Have Actually Been Planet Nine (sciencealert.com) 101
It's one of the most intriguing questions about the Solar System from the last five years: Is there a large planet, lurking out in the cold dark reaches, on an orbit so wide it could take 20,000 years to complete? The answer has proven elusive, but a new study reveals what could be traces of the mysterious hypothetical object's existence. From a report: Astronomer Michael Rowan-Robinson of Imperial College London in the UK conducted an analysis of data collected by the Infrared Astronomical Satellite (IRAS) in 1983, and found a trio of point sources that just might be Planet Nine. This, Rowan-Robinson concludes in his preprint paper, is actually fairly unlikely to be a real detection, but the possibility does mean that it could be used to model where the planet might be now in order to conduct a more targeted search, in the quest to confirm or rule out its existence. "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.
"However, given the great interest of the Planet 9 hypothesis, it would be worthwhile to check whether an object with the proposed parameters and in the region of sky proposed, is inconsistent with the planetary ephemerides." Speculation about the existence of a hidden planet in the outer reaches of the Solar System has swirled for decades, but it reached a new pitch in 2016 with the publication of a paper proposing new evidence. Astronomers Mike Brown and Konstantin Batygin of Caltech found that small objects in the outer Solar System's Kuiper Belt were orbiting oddly, as though pushed into a pattern under the gravitational influence of something large.
But finding the dratted thing is a lot more complicated than it might sound. If it is out there, it could be five to 10 times the mass of Earth, orbiting at a distance somewhere between 400 and 800 astronomical units (an astronomical unit is the average distance between Earth and the Sun; Pluto, for context, is around 40 astronomical units from the Sun). This object is very far away, and quite small and cold and probably not reflecting much sunlight at all; and, moreover, we don't know exactly where in the very large sky it is. So the jury is out on whether it is real or not, and the topic is one of pretty intense and interesting debate. IRAS operated for 10 months from January 1983, taking a far-infrared survey of 96 percent of the sky. In this wavelength, small, cool objects like Planet Nine might be detectable, so Rowan-Robinson decided to re-analyze the data using parameters consistent with Planet Nine.
"However, given the great interest of the Planet 9 hypothesis, it would be worthwhile to check whether an object with the proposed parameters and in the region of sky proposed, is inconsistent with the planetary ephemerides." Speculation about the existence of a hidden planet in the outer reaches of the Solar System has swirled for decades, but it reached a new pitch in 2016 with the publication of a paper proposing new evidence. Astronomers Mike Brown and Konstantin Batygin of Caltech found that small objects in the outer Solar System's Kuiper Belt were orbiting oddly, as though pushed into a pattern under the gravitational influence of something large.
But finding the dratted thing is a lot more complicated than it might sound. If it is out there, it could be five to 10 times the mass of Earth, orbiting at a distance somewhere between 400 and 800 astronomical units (an astronomical unit is the average distance between Earth and the Sun; Pluto, for context, is around 40 astronomical units from the Sun). This object is very far away, and quite small and cold and probably not reflecting much sunlight at all; and, moreover, we don't know exactly where in the very large sky it is. So the jury is out on whether it is real or not, and the topic is one of pretty intense and interesting debate. IRAS operated for 10 months from January 1983, taking a far-infrared survey of 96 percent of the sky. In this wavelength, small, cool objects like Planet Nine might be detectable, so Rowan-Robinson decided to re-analyze the data using parameters consistent with Planet Nine.
Or (Score:2)
EVIL from the 8th dimension! (Score:2, Funny)
Or maybe (Score:2, Insightful)
it may have been that thing called "Pluto" that was the ninth planet for decades until fairly recently.
Re:Or maybe (Score:4, Informative)
Re:Or maybe (Score:4, Insightful)
Did you hear a large whooshing sound as you typed that?
Did you read his comment? He is not saying the source of the readings IS Pluto and that Pluto was the ninth planet.
What they are looking for is planet X, ie the 10th planet. Pluto's current status is simply a victim of cancel culture. -Pluto is a planet.
In 2006, the International Astronomical Union members voted on formal definitions of what a "planet" is as there had never been any formal scientific definition. If they had not done so, dozens of other objects could be classified as "planets". For example, Eris is larger than Pluto and thus would have been Planet X. Objects like Ceres, Pallas, Juno and Vesta would all be "planets". And those are just the objects astronomers know about. There could be dozens of "planets" in the asteroid belt and the Kuiper belt.
But according to you, it was all about "cancel" culture. Sure . . .
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-Lighten up, have fun, it's the internet.
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The point is that no one really agrees with the new definition of a planet. Your examples where btw. already called "dwarf planets".
It is a typical decision by committee after a long week of talks when a huge deal of the participants on the conference already had departed home.
There could be dozens of "planets" in the asteroid belt and the Kuiper belt.
Exactly. And that is why it was a dumb decision to demote Planet Pluto.
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In fact, so many members had left that they didn't have a quorum, making that vote, along with any others taken that day, invalid. I think it's very telling that the motion wasn't brought up again in 2007 for confirmation because that implies that they weren't confident that it would pass again when most of the members were present and able to vote.
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In fact, so many members had left that they didn't have a quorum, making that vote, along with any others taken that day, invalid.
It's been over 15 years since that vote and in all that time, how many times has someone brought up a motion to reconsider the definition? Please cite the number of times and which conference it was brought up.
I think it's very telling that the motion wasn't brought up again in 2007 for confirmation because that implies that they weren't confident that it would pass again when most of the members were present and able to vote.
Considering that there was not a IAU conference in 2007 how could is the absence of something == confirmation of something?
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OK, then, at the next conference, then.
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So what's wrong with just calling all the dwarf planets... planets? I think it's awesome we've discovered lots of new planets every bit as significant as Pluto.
Having only a few planets seemed boring anyway.
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There's no physics-based system in which Pluto is planet #9. Any definition that includes Pluto in the 'planets' category also includes at least Ceres, and perhaps more of the asteroids.
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"There's no physics-based system in which Pluto is planet #9"
What if the definition were that the object be in an orbit of the Sun and of no other object?
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What if the definition were that the object be in an orbit of the Sun and of no other object?
That isn't really true for anything in the solar system though. Everything influences everything else, we just like to pretend that there are only two bodies involved to simplify the calculations. Even if we impose some other kind of qualifier (e.g. "at least 99% of its orbit is influenced by the sun"), it still gets fuzzy when you start getting far away because at pluto-esque distances, a close small object can influence your orbit a lot more than the massive distant object.
Re:Or maybe (Score:5, Informative)
Don't forget Ceres, Pallas, Juno, Vesta and Astraea, planet victims of 1851 cancel culture.
When discovered, Neptune was considered the 13th planet.
Ceres is now considered a dwarf planet like Pluto. But Pallas, Juno, Vesta and Astraea are now just Asteroids.
Re:Or maybe (Score:4, Informative)
And Eris, which is heavier than Pluto, and was considered the 10th planet when discovered just 16 years ago. Now she is considered a dwarf planet, too.
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They prefer to be called "little planets".
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When discovered, Neptune was considered the 13th planet.
Ceres is now considered a dwarf planet like Pluto. But Pallas, Juno, Vesta and Astraea are now just Asteroids.
With all those names, they should have been in this video [youtube.com].
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Ceres, Juno and Vesta are in the video using those very Latin names, and Pallas is named for Pallas Athene, who is in the video using her Latin name Minerva.
So only Astraea is missing.
Re:Or maybe (Score:5, Insightful)
It must be a very frustrating life to live where one cannot accept or adapt to the fact that a lot of the lessons you had learned while in elementary school have turned out to be more nuanced, reclassified, or just proven wrong over time.
I made this realization in 7th grade.
In 6th grade we were taught 3 Kingdoms of life, Animal, Plant, and Protozoa (Which included Bacteria, and Fungi, and was more or less just taught as a catch all group, which we didn't cover too much). In 7th grade, we got it broken out more Were Bacteria, Protozoa, Fungi and Ange were separated out. After that had happened, I learned a good lesson. Don't get stuck on memorizing where things are classified, but figure out why and how they are classified, and how we choose to classify things change over time, as we learn new things, challenge how we classify other things, and why they are different.
Re:Or maybe (Score:4, Interesting)
It must be a very frustrating life to live where one cannot accept or adapt to the fact that a lot of the lessons you had learned while in elementary school have turned out to be more nuanced, reclassified, or just proven wrong over time.
The issue is that astronomers no longer consider Pluto a planet. People can call Pluto a planet all you want but people who work in that field do not. Just like biology, the difference is merely the classification of things. Pluto did not disappear; what professionals classify it is different now based on new data.
Incidentally in biology, the move has been away from 7 rigid levels of classification as some organisms may have far more levels. The move is to use clades [wikipedia.org] which is analogous to computer folders or tree branches where you can have as many nested levels as you need to classify something.
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Re: Or maybe (Score:2)
Unlikely? Seriously? Unlikely implies there is a chance it is, but actually there is zero chance that it is Pluto. There is zero probability that any astronomer would mistake Pluto for anything. These are objects thousands of times fainter than Pluto. If they are going to mistake it for something it would be one of the thousands of Kuiper Belt Objects. Everyone knows where Pluto is and it is extremely bright on any serious observatory telescope.
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Yes I am aware of that, but in this case it is in the realm ridiculous. If you want to include ridiculous doubts you wouldnâ(TM)t be able to state anything without qualifiers. I mean would you say the moon is unlikely to be made of cheese? Yes it is possible the moon is made of cheese, but then not only would all the conspiracies would have to be true (which alone could be arguably in the realm plausible) but also all logic would be suspended too about possible origins of cheese. Mindlessly using the w
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Comet? (Score:2, Insightful)
Objects circling the sun with highly eccentric, long orbital periods that take them very far away for most of their orbit are usually called comets.
Re: Comet? (Score:4, Interesting)
Note how you say usually. That's the problem. The actual 9th planet is unusual in a sense of mass, it's close to the point we can call it an asteroid, debris left from something which still orbits our sun. The mass of this object makes it clear the rules we set last time though. As it turns out, naming things isn't trivial. The more interesting fact would be does this thing exist at all and did we really pinpoint it. If so, it's likely significantly bigger than Pluto
Not if they're several times massier than Earth (Score:4, Informative)
If it's a frosty dust bunny, sure. If it's a ball of rock several times the mass of the earth, not so much.
According to the 2006 definition, a planet is something that meets three criteria:
1. It must orbit a star (in our cosmic neighborhood, the Sun).
2. It must be big enough to have enough gravity to force it into a spherical shape.
3. It must be big enough that its gravity cleared away any other objects of a similar size near its orbit around the Sun.
So unless it's orbiting something bigger rather than the sun (in which case it gets to be a "moon") or in some mutual orbit or resonance system with another of its kind or other space junk and the two-or-more of them orbit the sun together, it looks like "planet" would be the correct term.
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2. It must be big enough to have enough gravity to force it into a spherical shape.
How close to spherical? Does it have to be a perfect sphere? Ellipsoid?
/. that the Earth is not perfectly spherical...
I hope it can be agreed upon on
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Bazillionaire toker Musk might not like his "trip" planners (multi-level pun not intended, in your head use a Hillbilly Jethro voice) telling him "Well, we turn this here rocket on for a little bit, and when we get cl
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Never bothered to check - did they ever define "near its orbit" in a way other than "I'll know it when I see it"?
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long orbital periods that take them very far away for most of their orbit are usually called comets.
Not really. A comet is an icy object that comes close enough to the sun to melt, gas out an atmosphere and have it ionized by the solar wind and make it glow.
If it was a rock, it would not glow, and would not be a comet.
Planet 10 (Score:1, Insightful)
Pluto is planet 9
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YES! Pluto was grandfathered in after the definition was changed.
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How about Sedna?
We don't know her weight yet, but its probably similar to Ceres.
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Planet, 2006 definition:
1. It must orbit a star (in our cosmic neighborhood, the Sun).
2. It must be big enough to have enough gravity to force it into a spherical shape.
3. It must be big enough that its gravity cleared away any other objects of a similar size near its orbit around the Sun.
Are Ceres and/or Sedna big enough that they squished themselves into essentially spheres despite the strength of their material? Did they clear out orbital gaps for themselves in the asteroid belt? If so, they qualify.
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What's wrong with having a consistent definition for a planet and call these other objects dwarf planets or whatever?
P.S. I mostly blame Charon for Pluto's demotion.
Planet X (Score:1)
Too bad it's not Planet X. My understanding is that we're running low on Illudium Phosdex, the shaving cream atom.
Planet 9 has (Score:2)
...many machines... , new machines, better than the ones on Richese
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This may be a typo (Score:2)
Planet 10 (Score:2)
The conference was over, 90% of the astronomers had left, when the remaining 10% decided Pluto was a dwarf planet, not a real planet. I have heard, over and over, including from a friend who's a well-known astronomer, that almost no real astronomers consider Pluto anything but planet 9.
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IRAS rocks (Score:2)
This little spacecraft from ~40 years ago, with a mission life of under a year, just keeps on giving.
They already know (Score:2)
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Even further out? (Score:1)
What if it's more massive than they though, and even further out? Something terrifying like a black hole orbiting our solar system, waiting to nom us up.
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If it's orbit is stable, wouldn't it take something pretty massive falling into it (or absorbing it) to start nomming the solar system? I mean, it could make for some interesting theoretical hard sci-fi, but I'm not too concerned even if it is a black hole that I or any children's children down the line from my family would have to worry about it for a long time to come.
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Well, realistically if it was ever going to happen I'm sure it's like, millions or billions of years out depending on it's orbit if it's stable or not and so on. Black holes are just cool and terrifying things either way in my opinion. I didn't mean to imply it's like some sort of immediate danger.
Just waiting for the day when we figure out how to leave our solar system and someone is like oh shit oh shit oh shit as they left at the wrong orbital period.
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I don't get the "terrifying" bit, because if it were orbiting the Sun, in the outer part of the Solar system, then it has been there for about 4.5 billion years and, pending something changing the gravity field of the Solar system, it isn't going anywhere but on the orbit that it has been on for 4.5 billion years.
Beside, if there were a black hole in the Kuiper belt, then we'd see X-rays from the solar wind interacting w
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I just think black holes are as much neat and interesting, also terrifying conceptually given the forces they exert. I wasn't trying to imply some sort of immediate danger. You know, just something ominous lurking in the not too far unknown.
Which (now this is the complicated bit) we don't.
Not sure if you're just trying to be a smartass there or something. If you could just step away from that, that'd be great. I'm sure you could be right, as it would have to be quite close to really only affect the outer regions of our solar system which would make it clo
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Hmmm.
Now that is a question. Would the frame-dragging of a rotating black hole impose a directionality on the emissions from an accretion disc?
I can't think of a process in a sheared spacetime (rotationally sheared, laterally sheared, or something more exotic) that would influence the direction of emission of thermal photons. OR Hawking photons. The sheared spacetime itself may well "beam" the radiation out along t
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TL;DR I asked a question, I didn't make a statement, hence it cannot be wrong. Sit down, you're getting ahead of yourself, and spell check before being an asshole, the internet is well known to call that out when someone is being a prick.
Sorry, I come from a generation where if people made mistakes they were called out on it. Also, it was possible to fail an exam. I do realise that "prizes for everyone, and nobody loses" is the current childcare paradigm, but that doesn't make me think it's right and certainly doesn't encourage me to follow it.
Okay, I made an innocent suggestion, you decided you wanted to be condescending about it. Instead of letting it go, you decided to double down on it.
First off, if you're going to be critical and condescending to people, spell check your work. You spelled realize wrong. You
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Not even close. You were being smug arse and pushing for a response. You got one, so sit down.
The weird part about this is... (Score:2)
it could be five to 10 times the mass of Earth...very far away, and quite small and cold and probably not reflecting much sunlight at all
So, it's made of some sort of exotic matter? I'm assuming "quite small" means smaller than Earth. But if it's 5-10x more in mass, it's made from what? Earth is 5.514 g/cm^3 which is less than the density of iron, (7.874 g/cm^3), which makes sense since it's not 100% iron. But if you 5x or 10x that number, you're looking at an average density that's way off the viable section of periodic chart of elements.
Did we finally find unobtanium?
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You're misunderstanding the descriptor "quite small".
Jupiter has roughly 11X the diameter of Earth, ~88K km vs 8K km. If we cube that ratio to compare volumes, we could fit about 1,300 Earth-sized objects into one Jupiter-sized object.
Even if Earth were 10X its current volume, it would still be tremendously smaller than Jupiter. So something could be significantly larger than Earth and still be small, in the grand scheme of things.
There are three things that affect the visibility of objects in the solar sys
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Well, what's the baseline for "quite small", "small", and "normal"?
I was operating under the assumption that they were going at it from an Earth-centric view, with Earth being "normal" sized. But I just did the math, and Neptune is "Average sized" in our Solar System, with a radius nearly 5X that of Earth.
It's still kinda confusing.
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Since I'm not interested enough to read either article, did you get the "quite small", "small" or "normal" from the Arxiv paper, or the ScienceAlert journalism?
Hint : don't expect precision from journalism. Read the paper.
(Kudos to msmash though, for linking to the paper.)
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Check your sources.
Neptune is a bit less than 4 time the diameter (or radius) of Earth, so about 64 time it's radius (elementary geometry), 17 time it's mass, and about 1/3 of it's density.
You can't actually easily compare mass, geometry and density, except in the smallest of bodies (smaller than Ceres, or so). Once you get more than a couple of thousand km below the surface (be it a "rocky"
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For reference, the earth’s circumference is r
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So, is 2x the size of Earth "quite small"? I would have figured "quite small" would be Pluto. Or Mercury.
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The first binary digit is right, but I doubt the second.
You've neglected gravitational compression, as I've just described in a reply to Reeses' GP message.
A 10 Earth-mass planet would have a diameter considerably less than twice that of Earth, even if it was made of the same materials in the same proportions. But add (say) 2% by mass of water and you'd possibly balloon
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I never eve
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It's important. Sometimes even at the first binary digit.
I do my Slashdottery on a plugged in laptop. If you're going to try to consider "sciency" things, and "stuff that matters", you really need to check your own working.
If I find myself using a bit of astronomical data often enough to think "I looked that up a few weeks ago", I tend to shove it - and possibly a ready-reckon
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Oh, absolutely. A cubic metre is a cubic metre, but it doesn't always contain a tonne of water.
It's been a while since someone has told me, here, that water is incompressible after I have told them that it is. Invariably, they're talking about the low pressure (300 atmospheres, that sort of thing - down where my consumer grade diving bottles get tested) systems that they are familiar with, and I am talking about medium pressure systems
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Your friend was working with seawater. That is - in "oilfield units" - 8.34 ppg. But fresh water - such as you need to use for pre-hydrating your bentonite at several hundred pounds per barrel concentration - is 8.0 ppg.
I did a job once for a French company, working on a field originally drilled by Americans and Brits, with an American "company ma
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I found a lovely bug in our depth-managing software when I worked on a job on the shores of the Caspian Sea. Can you guess what it was?
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Plenty of asteroids are considered pretty massive/solid in the sense that they perhaps mostly contain one element only: carbon, iron, gold, iridium etc.
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Please cite your sources - from science papers, not meaningless journalism.
For example, the popular (for asteroid-mining fans) "metal asteroid" 16 Psyche has a density of about 3800 - 4000 kg/cu.m meaning that it can only be "pure" metal if it is made of aluminium. If it is a mixture of iron and nickel - like the metallic meteorites we sample from the asteroid belt by hitting them - then it is about 50% by volume metal and 50% olivine (or other iron-rich silicate minerals), which would make i
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C'mon Angelo - you've got a brain quite capable of handling reality. Why are you making such unrealistic claims?
Because that is what I learned in school and university.
No idea if it is unrealistic ... you tell me?
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Our best evidence for the composition of asteroids is meteorite falls (which we've add spectroscopy to in the last few decades) and the composition of (say) pallasite meteorites (olivine-iron meteorites, named for their original classifier, a Russian by name of Pallas in the late 17th/ early 18th century. Put almost any of the technical terms in this reply into Wiki, and you'll get more references than you'd want to read.
This stuff was in the text books on astronom
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I don't get your point.
You are referring now to meteorites which are nearly 100% iron.
So?
This stuff was in the text books on astronomy and geology that I read in the 1970s.
Exactly. Probably the same books I read.
So: what is your damn point?
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I pointed out that the closest approach to that - so called "iron" meterorites - are at absolute best composed of two elements - iron and nickel in approximately equal quantities (but in several phases - remember the Widmansatten pattern [wikipedia.org] - that's the two phases interdigitated). Far more meteorites are "stony irons" (Pallasites etc) which add elements silicon, oxygen and magnesium to the iron and nickel for FIVE elements. And mete
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You were claiming that asteroids exist which are composed of a single element.
Correct.
And no idea what your objections is. Unless you want to point out that most of them have an aggregation of "other elements" on top of them, like simple rock.
My damned point is that you made a claim, and I refuted it, with evidence. Got it now?
I got your point now. But: you did not refute my point. You simply started a completely pointless nitpicking discussion.
And meteorites (and their asteroid progenetors) with more compl
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Who the hell (apart from you) is claiming that?
People have made claims that their calculations of the iridium mass-balance budget for the "KT-clay" layer suggests a more asteroidal (Bulk Silicate Chondrite) than cometary ("dirty snowball, with some grit) impactor, but even at that level they're talking about an average meteorite (chondrite - a dozen major elements and a few dozen more minor elements) versus an approximately average meteorite, with a
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Who the hell (apart from you) is claiming that?
The people doing such geological investigations and pointing out that there is a thin iridium layer fitting the date.
So: no idea what your which hunt is about.
If you've got a paper claiming what you assert : journal, volume and page (lead author as a cross-check ; title similarly). If you haven't got that, your claim is not worth considering.
Again: I dod not claim anything. I repeated my school knowledge.
And: no, I have no paper. And I'm not googling now for an
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Again: I dod not claim anything. I repeated my school knowledge.
Then your memory, or your schooling, is wrong.
If that's what you took away from your schooling, then you've missed three important little letters : "ppb". The "iridium spike" (when you plot multiple measurements of iridium content from a sequence against distance along section - which is a proxy for time ; sometimes it's combin
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If that's what you took away from your schooling, then you've missed three important little letters : "ppb". The "iridium spike" (when you plot multiple measurements of iridium content from a sequence against distance along section - which is a proxy for time ; sometimes it's combined with microbiology and/ or magnetostratigraphy to assign exact dates to the sample positions) is parts per billion ("ppb") of iridium in the sediments, not claiming that there was anything approaching a single layer of iridium
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Planet 9 is the (Score:1)
...budget deficit. It sucked in all the good asteroids and is now coming after Earth.
Why Pluto really is a planet (Score:2)
It seems like most of the debate on this page is whether Pluto is a planet or not. So let's dive into the definition for a moment.
1. In orbit around the Sun.
This is just a back-handed way of saying "no moons allowed." When you consider that there are literally billions of things in orbit around the Sun, but only a few hundred "moons" in orbit around something that's not the Sun, this requirement filters out a vanishingly small number of things. Add to that the fact that "cleared the neighborhood" renders th