Huh? When did this happen? Can I have a cite for that please?
::mutters under breath:: Turn my back for one minute and all theoretical hell breaks loose…
Romana
Well, I don’t know when exactly it happened, but I’ll take a stab and say mid 70’s. The latest paper I can find discussing the origin of asteroids as a planet that broke up is from 1977 and all I can say is Irish Astronomical Journal?? I found a cite from a more prestigious journal (Icarus) from 1974.
Here’s a pretty technical discussion which states, “It is believed that a planet never accreted in the asteroid belt because of the influence of massive Jupiter.” I’ve never heard the planetary disruption model from an asteroid expert, except to say that this is a discarded theory.
Unfortunately, many public-level websites (e.g. Zoom Astronomy, Explorezone) still mention the planetary break-up hypothesis, so you’re not to blame for not keeping up. 
Most do say that the planetesimal explanation is “preferred” or “favored,” which is a bit of an understatement.
Here’s the reasoning: 75% of asteroids are classified as C-type. C-types are dark colored and rich in carbon compounds. Their reflectance spectra are similar to carbonaceous chondrites, a class of meteorites. If the carbonanceous chondrites had been heated and melted at any time in their history, their chondrules would have been melted and mixed with the rest of the rock. This shows that chondrites were never part of a large planet, because larger bodies (say, a few hundred km in diamter or so) are slow to cool, so heat, mainly from the decay of unstable radioactive isotopes, can completely melt the body. (I’m going nuts trying to find a good cite for this, but the part of my brain that Googles seems to have shut down. Here’s a mediocre cite.)
Some types of asteroids, e.g. S-type and M-type, are believed to be part of bodies that were melted, separating so that the rock floats to the surface and the metal sinks to the center. A surviving example of such a large body is the largest asteroid, Ceres, which is 900 km across.
Ah, I’ve finally found a real slam-dunk of a cite:
http://abob.libs.uga.edu/bobk/ccc/cc030399.html
This article does a nice job summarizing current thought on asteroids at a moderate-to-high technical level. The authors are reputable authorities in this field.
Crud. . . forgot a couple of definition. Chondrites are meteorites that contain chondrules. Chondrules are small spheres of silicon. If you don’t believe me about that, look it up in the dictionary. My citifying organ is all worn out. 
I might as well weigh in here.
Let’s posit a planet much like Jupiter orbiting the Sun every 3600 years. That makes the semimajor axis of the planet about 235 AU, or 235 times the radius of Earth’s orbit (for those keeping track, the period of a planet sqaured equals the semimajor axis cubed: p^2 = a^3).
The brightness of a planet drops roughly as the fourth power of its distance from the Sun. That’s because the light it gets from the Sun drops as distance squared, and the light we receive from the planet here on Earth also drops as the distance squared. Multiply and get distance^4.
Jupiter is 5 AU from the Sun. That makes Nibiru 235/5 = 47 times farther away, which would make it 47^4 = (about) 5 million times fainter than Jupiter appears from the Earth. That makes it about 17 magnitudes fainter than Jupiter. Jupiter shines at magnitude -2 or so, so Nibiru would be at 15. That is not a whole lot fainter than Pluto, which, I note, was discovered in 1930, and would be easily rediscovered today using modern techniques.
I am fairly familiar with the search techniques used for looking for trans-Neptunian objects, and a 15th mag planet moving at the rate for a 235 AU orbit would have been seen a long time ago.
This is just one simple calculation anyone with a basic astronomy textbook can do. I won’t go into the high number of other astronomical errors Sitchin makes (as well as Velikovsky, from whom Sitchin borrows extensively). The idea of a planet tooling through the solar system causing the events Sitchin describes is not just impossible, but really, really impossible. Velikovsky’s physics have been thoroughly debunked elsewhere. I invite you to look it up on the web.
Thank you, Podkayne.
Romana
Bad Astronomer, nice back-of-the-envelope estimate!
Just to play devil’s advocate, though, Marduk’s orbit is supposed to be highly elliptical. I don’t believe Sitchin gives a value for its eccentricity, but I suppose one could estimate it based on how close its closest approach to the Sun should be.
This means that Marduk could be much farther out than the average distance of 235 AU you use for your estimate. How much farther? No clue, since Sitchin’s student seems to have bailed and he didn’t say when it last reached perihelion.
This would have two significant observational effects:
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It could be much fainter than you estimate.
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Its velocity at aphelion would be glacial, making it difficult to find since their orbital motion is only way we have to distinguish distant solar system objects (like TNOs) from faint background stars.
On the plus side, it’s clearly confined to the ecliptic since it has close encounters with so many planets, so you won’t have to search the whole sky for it–unless one of those encounters gave it a significant inclination, a possiblity that doesn’t seem to occur to Sitchin.
Here’s an recent Discover magazine article on a search for large, distant planets in our solar system by scientists whose work would be labeled “fringe” rather than outright pseudoscience: http://www.discover.com/oct_01/featplanets.html
Sure, that does detract from my argument. We can actually make an estimate of the eccentricity of the orbit, given that we “know” the period and that it must have a perihelion of at most 1 AU, to get it close to us. For a 3600 year orbit that eccentricity is pretty close to 1 (actually, 0.9997 is about right). It really would spend most of its time a long way out; a weakness in my argument. The aphelion would be about 470 AU, making it something like 78 million times fainter than Jupiter, or 20 magnitudes fainter, about mag 18. That’s still pretty bright.
Also, it does move, even when farther out. People make it their job to check for movement in objects over time, and it strikes me as difficult to believe something like this would get missed. I may be wrong though. [note that this is how I differ from a pseudoscientist: I admit when I am wrong.]
Anyway, this does bring to mind another problem: if this planet gets so close to Uranus that it tips over, blows Pluto away from Saturn and even tips over the Earth, then a lot of energy is exchanging hands. With an eccentricity so close to 1, a stiff breeze would launch that planet on a hyperbolic orbit, never to be seen again. It seems unlikely it would survive more than one such encounter.
Which is another reason I have such a hard time with such theories. Space is big, yet these guys would have a planet knocking on the door of just about every planet in the solar system, sometimes missing us by a mere 1000 kilometers (Velikovsky needs Venus to miss us by only hundreds of kilometers, since he supposes we actually exchange atmospheres with it). It takes NASA a lot of effort to get this close to one planet, let alone many planets in multiple encounters using a single probe.
Sitchin, Velikovsky and the rest don’t seem to understand just how vast space is, and how tiny planets are geometrically. The general public doesn’t either, which is why it is so easy to gloss over points like these in books. Once you apply a bit of math, these claims tend to evaporate like so much manna in the hot sun.
I wanna have the Bad Astronomer’s baby… 
BTW, did you know Google has a category for something called “Alternative Physics”? That’s right–if you put in “Velikovsky physics”, the first entry comes up under Category > Science > Physics > Alternative. Silly me, I thought physics was physics. Well, well, well… Is there also “alternative astronomy” around here somewhere?
Anyway–Skepdic summarizing Carl Sagan on Velikovsky. Cool stuff.
http://skepdic.com/velikov.html
Incidentally, after further thought, I must admit that for a long time centered on aphelion such a planet would indeed be hard to detect. The TNO surveys are designed to look for objects moving at a certain rate, which is much faster than something at 400 or so AU. They could miss such a planet.
I’ll note that there is no reason a priori to assume a planet exists that far out, and there is some evidence that there is none. No one knows, however. It might be prudent to search for one, but not because of Sitchin and his pseudoscientific brethren. Instead, there is circumstantial evidence in other stars that planets may exist very far out from the central star. We see no evidence that the Sun has such a planet, but we don’t really have any evidence to rule out one very far out (we do know that no Earth-sized or bigger planet exists closer in than about 75 AU, though, from planetary position measurements). It would be pretty cool to find one. But I’ll bet just about any amoiunt of money it won’t be on an orbit like Sitchin predicts.
By the way, DDG, I already have a kid. Thanks for the offer anyway.
Just a quick word on how they search for TNOs. . .
They take several images of the same stars. They know that the objects that they’re looking for will be moving at a certain rate across the sky, so that it will move inbetween one image and the next. The astronomers shift each image by the distance that an object moving at this rate would travel in the time between the images. Then they combine the images together. This smears out the stars because the stars, of course, are not moving and are therefore uninteresting. But if there are any objects in the image moving at the right rate, then after shifting and adding, the object’s light will be combined all at one point, and it’ll look nice and bright. They count each object they find this way, and measure its position and note its rate. Then they assume a slightly different rate of motion, and repeat the process.
So if there’s an object in the image that is not moving at the rates the astronomers check, they won’t find it–though I think they would notice a 15th magnitude “star” that’s not on the charts!
As a side note, does Sitchin actually advocate searching for Marduk? It seemed to me he already had all the evidence he needs . . .
That is one of many methods… it was used in Hubble images a few years back. It makes me nervous, because it presupposes the speed and direction of motion of the TNOs. Another way is to subtract digital images and look for anything left over. Stars which don’t move should subtract to 0, and anything that moves will leave a positive bump and negative hole. That’s a really difficult way to do it (cosmic rays mess things up, as do changes in focus, atmospheric conditions, blah blah blah), but it can be semi-automated.
The point is, it can be done, has been done, and has been shown to work.
Hey Folks:
No, I’m still here. Haven’t checked back here in a few days, sorry to alarm everyone. The responses lately have all been very detailed and dispassionate - thanks for explaining and not railing. I’m still thumbing through the Sitchin books trying to find where he mentions the period observations of the planet Nibiru, as someone on here asked for. Not there yet, but be patient!
In the meantime, here’s something Sitchin has on his own website, and this all a quote:
<<<"Far beyond the solar system’s nine known planets, a body as massive as Mars may once have been part of our planetary system – and it might still be there;”
The lead paragraph in a science-fiction script?
The lead paragraph from an article by Zecharia Sitchin about Nibiru?
No. It is the lead paragraph in a report in Science News of April 7, 2001 headlined "A Comet’s Odd Orbit Hints At Hidden Planet.”
The article reports the conclusions of an international team of astronomers who have studied an unusual comet discovered last year, designated 2000 CR/105. It follows a vast elliptical orbit around our Sun – an orbit that takes it way out to some 4.5 billion kilometers from the Sun, and brings it back at its closest to the Sun to the vicinity of Neptune; it is an orbit whose period “takes roughly 3,300 years” (according to Sky&Telescope News of April 5, 2001).
“Such an oblong orbit is usually a sign that an object has come under the gravitational influence of a massive body," wrote R. Cowen in Science News. Was this the gravitational pull of Neptune? In a study to be published in the Journal Icarus, the team of astronomers (led by Brett Gladman of the Observatoire de la Côte d’Azur in Nice, France), after analyzing all the possibilities, does not think so. An alternative solution, they say, is that “the comet’s orbit could be the handiwork of an as-yet unseen planet” – as massive as Mars – “that would have to lie some 200 AU from the Sun,” in the so-called Kuiper Belt of cometary and other planetary debris. This would also explain “why many members of the Belt have orbits that angle away from the plane in which the nine known planets orbit the Sun.”
“Undoubtedly, something massive knocked the hell out of the Belt," Harold F. Levison of the Southwest Research institute in Boulder, Colorado, told the magazine. “The question is whether it is still there now."
“Comet’s Course Hints at Mystery Planet,” was how the journal Science headlined the discovery news in its issue of 6 April 2001. The special report, written by the Dutch astronomer Govert Schilling, summed up the findings in the following lead paragraph:
“A Supercomet following an unexpectedly far-flung path around the sun suggests that an unidentified planet once lurked in the outermost reaches of the solar system, an international team of astronomers reports. What’s more, the mysterious object may still be there.”
Now, As the Sumerians Said…
Readers of my books may well join me now in saying: So what else is new?
Ever since the publication of my first book (The 12th Planet) in 1976 I have asserted that Sumerian and other ancient Near Eastern texts and depictions showed familiarity with a complete Solar System that included, beside the Sun and the Moon, ten (not nine) planets – the tenth planet (or twelfth member of the Solar System) having a vast elliptical orbit that lasts 3,600 years. Its Sumerian name was Nibiru.
I have-suggested that Sumerian/Akkadian texts such as Enuma Elish (also called the Babylonian Epic of Creation) were not mythological tales, but records of sophisticated advanced knowledge. Establishment scientists and scholars (see a previous article, The Case of the Misplaced Teapot, as an example) resist such an inevitable conclusion because it requires the acceptance of the ancient claim that Earth had been visited by Extraterrestrials, the ANUNNAKI (“Those Who From Heaven to Earth Came”) of Sumerian lore.
According to the ancient texts as interpreted by me, Nibiru was a planet ejected from some other planetary system in outer space that was captured into our Solar System as it passed near Neptune. It became involved in a collision with a pre-existing planet where the debris of the Asteroid Belt are now. As a result of that collision, some 4 billion years ago, the Earth and the Moon came to be where they are now.
And, what do you know? In an article titled Neptune Attacks! In the 7 April 2001 issue of the magazine New Scientist, Ivan Semeniak wrote thus:
“There is new evidence that a sudden barrage of deadly debris crashed against the Earth and the Moon 3.9 billion years ago… What triggered this onslaught? Something in the structure of the Solar System must have changed.”
The “something,” I am more certain than ever, was Nibiru.>>>
So there is some grist for the mill, and maybe someone (Podkayne, BadAstronomer, Duck?) will see something in there that needs to be eviscerated. So this is no rebuttal, but it’s all I have at the moment. I looked over the Skeptic website, and found nothing on Sitchin, btw.
From your Opening Post (or “OP,” as we call it here):
So it’s Sitchin’s claim that these extraterrestrials’ home planet was somehow ejected from another solar system, it traveled through empty interstellar space for a time, encountered our solar system and became captured by our Sun? And that the Nephilim somehow survived that trip through interstellar space?
Excuse me, but if a planet were somehow ejected from its native solar system, it would attain a speed much, much less than the speed of light, so it would have to take thousands of centuries to reach our solar system, even if the origin was the Centaurus system, the nearest star to our Sun. (A triple-star system 4.3 light-years away, about 25 trillion miles. And it doesn’t appear to have planets.)
Except that if you read Page One of this thread again, you’ll see a post by Podkayne that explains why it is no longer believed by professional, expert astronomers that the asteroids are the remains of a destroyed planet.
I hope that either Bad Astronomer or Podkayne can explain how this is wrong. If the Earth and Moon were once in substantially different orbits 4 billion years ago, surely there would be a way to know.
If it happened 3.9 billion years ago, how could the ancient Sumerians have known about it?
You should have tried the Skeptic’s Dictionary.
Here’s an interview with Sitchin that I found through the link to SkepDic via Jab1. It will help readers understand the premise behind Sitchin’s work, so check it out.
Typical shotgun approach. Ignore criticisms, and keep throwing stuff against the wall hoping something will stick.
Don’t be such an ass, Podkayne. I’m not devoting all my time to this thread. I already said I’m looking up some of the answers to questions that have been posed. Is that too shotgun for you? I went out to a (gasp!) rock concert last night, instead of looking shit up for you. How could I be so insensitive?
Here’s the deal folks: it really doesn’t matter to me if any of you subscribe to Sitchin’s theories, or if you think he’s a crackpot. That’s your business and I don’t give a good goddamn what you do with yourselves. I think Sitchin has some answers. It may very well be true that his physics models are flawed, that he understands nothing about astronomy, and that the existence of extra-terrestrials is all crap. I’m trying to take the time and look at the sites people have been posting, to find out if Sitchin’s claims are specious. That AU distance brightness stuff is not in my bailiwick. I’m examining that stuff and trying to make sense of it. I have no credentials or training in this stuff and never claimed otherwise. Also, I don’t buy these “arguments” that are merely cut-and-paste bits from other people’s work. I won’t just accept it because someone has posted it. I am looking it up for myself. If this strikes some out there as too slow, tough. What are your qualifications, Podkayne? I used to think anyone that used a handle taken from a Philip K. Dick book couldn’t be all bad, but you’re quickly proving me wrong, yet again! Is there no end to the madness???
While this may be religion and a matter of life and death to some of you, it’s just a lark for me. I’m enjoying the Sitchin books, and I’m happy to read links and sites that explore/trash/debunk those books, but I’ve had enough of your petty bitching. It’s like showing up late at a Star Trek convention and not knowing what Episode 76 was all about, and getting taken to the mat for it. I only hope that during your working hours, as you file and add up numbers, that you can think up some really withering criticisms to post back here.
Oh yeah, and did I say, get a life?
Anvil, unfortunately, if you keep it up with the personal insults and the snotty voice, Dex’ll toss this puppy into the Pit. Snotty voices in Comments make Baby Dex cry. You think the knives are sharp here, in Comments? Wait till you experience the Pit. Think “Texas Chainsaw Massacre”.
Okay, now, Jab, Podkayne–we are all gonna be REALLY REALLY polite from now on, 'kay? Think “kid gloves”, people. Please. 'Cause I personally am getting into this, and I don’t wanna have to wade through 20 posts of “fuck you/oh yeah? Fuck you” BS to get to the good parts, even if the discussion as such doesn’t for all practical purposes die an immediate and horrible death, suffocated by a barrage of Anglo-Saxon euphemisms for bodily functions.
And did I mention how much I enjoy listening to the Bad Astronomer talk? Now, he don’t hang out in the Pit much. So let’s all put our Happy Faces on and make ourselves useful, go look up Govert Schilling or something.
Schilling’s article is probably not posted on the Web. There are only 3 Google hits for the words “Supercomet following an unexpectedly far-flung”, which are the opening words of its first paragraph. Of those 3 hits, one is Sitchin’s, one is a word-for-word Copy and Paste of Sitchin’s website, and the third, interestingly enough, is a website debunking Sitchin:
This is neither intended to be inflammatory, a slam against you, or an ad hominem attack. However, I gently ask you this: if you said:
Then why post about this topic? Clearly, you were commenting on Mr. Adam’s essay on this topic, but to post in the Comments section is to invite, well, comments. Not all of them will be polite, I have found (on any board, even my own), but it seems clear you do care what others think, or else you wouldn’t have posted.
First, wonderful! I deal with a lot of people who have ideas contrary to mainstream science (to be really polite about it), and it is a rare case who doesn’t merely parrot what he has read. I’m truly glad (no sarcasm at all) that you are reading more about this.
The stuff about brightness was sort-of an aside between Podkayne and me. Basically, a planet on an elliptical orbit moves faster when it’s close to the Sun, and much slower when it’s far away. That means it spends most of its time far from the Sun. I did some quick-and-dirty numbers to figure out how bright it would be that far out, and I get that it is still bright enough to be seen easily in professional telescope surveys. However, any purported planet would be creeping along, and may elude detection, especially if the surveys are looking for objects moving at certain rate.
Again, not to be inflammatory, but that is part of the problem. Indeed, it’s the very heart of it. Someone comes along with scholarly credentials, making claims that fly in the face of conventional science. These claims make sense, sort of, and the tale they spin appears to hold together. The problem is, they are very rarely quantitative, that is, use actual physics and math to prove the point. Velikovsky was the first in modern times to do this. He makes pretty wild claims about a celestial pinball game occurring in Biblical times, but the instant you apply math to it it dissolves. That has not stopped people from inventing all sorts of alternative physics to account for the original story. The problem is, it never works. And unless you apply the math, you can’t really judge the idea on its merits.
There is a story that Carl Sagan met an archaeologist, and they were discussing Velikovsky. The archaeologist said to Sagan, “Velikovsky’s archaeology is garbage, but his astronomy sounds quite interesting.” Sagan replied, “I was going to say that his astronomy is garbage, but his archaeology is intriguing!” The point: outside your field, it is possible that things sound coherent, but to someone familiar with the field, the jig is quickly up.
I don’t know if you’d call me an expert on all things astronomy, but I am a professional astronomer. I have never seen any claims by Biblical catastrophists that hold water, including Sitchin, Velikovsky and the latter-day Velikovskians (who call themselves Kronians now). I have applied enough math and physics to some of these ideas to show to myself and others that the basic stuff they say (planetary encounters causing catastrophes) is literally impossible. I won’t go into it here, because it would be very long to describe (as if this isn’t already!). I just wrote a chapter in a book about Velikovsky’s astronomy, and hopefully I may write up more for my website sometime.
Actually, I sometimes do. Defending the honor, and all that.