Asteroids of the Asteroid Belt

[Robittybob1]

As I said yesterday "Take the asteroids of the Asteroid Belt I would guess that they all have a similar isotopic profiles too due to the fact they were all accreted from the same region of the protoplanetary disc." (spelling corrected)

 

Does anyone know?

 

All I could get from a video on the Dawn Mission was that of all the meteorites striking the Earth some percentage are known to have come from just 3 bodies, Mars, the Moon and Vesta (protoplanet of the Asteroid Belt).

I presume there are many more from unknown origins. Will there be a way of knowing where they come from?

NASA site define asteroid belts this way:http://www.nasa.gov/multimedia/imagegallery/image_feature_1651.html

 

Asteroid belts can be thought of as construction sites that accompany the building of rocky planets.

So there is a region in space orbiting a star where you find this construction site. Now what I contended is that over a period of time the objects in the belt are becoming mixed. This would be due to collisions affecting the speed of the objects and hence their orbital period. Larger protoplanetary sized bodies would not pass each other very often but the physics would not disallow this. The laws of physics would mean that Vesta and Ceres could pass each other in orbit. They might have established a resonance with another planet or each other which makes this less likely. Does anyone know?

 

Vesta Orbital period: 1,325 days

Ceres Orbital period: 1,680 days

 

If this is true for the larger objects surely the same applies to the smaller objects in the Asteroid belt.

It appears someone has calculated the chances of Ceres and Vesta colliding.

 

 

Calculations of the orbital evolution of two major objects of the main asteroid belt, the dwarf planet Ceres ans the asteroid Vesta. showed that in the future they may collide.The collide of Ceres and Vesta possible with a probability of 0.2% per billion years. Laskar and his colleagues conducted computer simulations of the evolution of the solar system, considering the behavior of the eight planets, Pluto, Ceres, and the four largest asteroids Pallas, Vesta, Iris and Bamberg, located in the main asteroid belt between Mars and Jupiter. Analysis of the gravitational interactions of these celestial bodies showed that the convergence of the asteroids in a very short time in astronomical terms, “thrown into chaos” their orbits, that is, after a certain period of time, their orbits become essentially impossible to predict.

Read more: http://forcetoknow.com/space/happen-ceres-vesta-collide.html#ixzz3zQ11IW2r

So that makes it rather a slim chance.

Edited February 6, 2016 by Robittybob1

[Ophiolite]

As I said yesterday "Take the asteroids of the Asteroid Belt I would guess that they all have a similar isotopic profiles too due to the fact they were all accreted from the same region of the protoplanet disc."

 

Does anyone know?

And I suggested that rather than guess you should do some research. Had you done so you would not needed to have asked the question.

 

For example, here

 

Greenwood, R.C. et al "Oxygen Isotope Variation in Stony-Iron Meteorites",Science Vol. 313 22 September 2006

 

Abstract:

Asteroidal material, delivered to Earth as meteorites, preserves a record of the earliest stages of planetary formation. High-precision oxygen isotope analyses for the two major groups of stony-iron meteorites (main-group pallasites and mesosiderites) demonstrate that each group is from a distinct asteroidal source. Mesosiderites are isotopically identical to the howardite-eucrite-diogenite clan and, like them, are probably derived from the asteroid 4 Vesta. Main-group pallasites represent intermixed core-mantle material from a single disrupted asteroid and have no known equivalents among the basaltic meteorites. The stony-iron meteorites demonstrate that intense asteroidal deformation accompanied planetary accretion in the early Solar System.

It took less than one minute to locate that example. If you care to do even a cursory search you will find many other examples, including ones that discuss more subtle variations.

[Robittybob1]

Thanks but from that I can't tell if it supports my OP statement or not.

What inference did you get out of it?

Was the material in the Asteroid Belt mixed prior to accretion or not?

Not all asteroids have their origin in the Asteroid Belt.

Edited February 6, 2016 by Robittybob1

[Ophiolite]

Not all asteroids have their origin in the Asteroid Belt.

 

Take the asteroids of the Asteroid Belt I would guess that they all have a similar isotopic profiles too due to the fact they were all accreted from the same region of the protoplanetary disc

 

Really? You don't see a problem with these two statements? Answering your questions is generally a waste of time RB, since you rarely understand what you are asking and never seem to understand what you are told.

 

Thanks but from that I can't tell if it supports my OP statement or not.

What inference did you get out of it?

I got no inference from it. I got the definitive statement that, contrary to your claim, different asteroids have different isotope ratios.

[Robittybob1]

I think I'm getting a better understanding of it now. There are families of asteroids and not all of these are in the Asteroid Belt e.g the Haumea family is "beyond Neptune's orbit".

Within the families there could be isotopic similarities. I never claimed there will be no difference in the isotope ratios I just said "similar".

These families are found in regions, even regions within the Asteroid Belt so there was not complete mixing in the Belt prior to accretion.

OK I accept I was not fully correct in my guess, but there are regions of the Asteroid Belt and families of asteroids which do suggest similarity of some degree.

[Robittybob1]

Does anyone care to agree that there is partial mixing in the Asteroid Belts prior to accretion (using the NASA idea that they are planet construction zones).

OK I accept I was not fully correct in my guess (that Asteroid Belt bodies would have similar isotopic arrangements) but there are regions of the Asteroid Belt and families of asteroids which do suggest similarity of some degree blending.

 

The larger Asteroids appear to have internal structure.

 

Ceres appears to be differentiated into a rocky core and icy mantle, and may have a remnant internal ocean of liquid water under the layer of ice.[19][20] The surface is probably a mixture of water ice and various hydrated minerals such as carbonates and clay. In January 2014, emissions of water vapor were detected from several regions of Ceres.

The process of differentiation implies that there will be different minerals or materials found on the surface and deeper in compared to the asteroids that were called rubble piles (non-differentiated).

So after an impact resulting in ejecta some of these samples are found on Earth as meteorites.

[pavelcherepan]

Does anyone care to agree that there is partial mixing in the Asteroid Belts prior to accretion (using the NASA idea that they are planet construction zones).

OK I accept I was not fully correct in my guess (that Asteroid Belt bodies would have similar isotopic arrangements) but there are regions of the Asteroid Belt and families of asteroids which do suggest similarity of some degree blending.

 

The larger Asteroids appear to have internal structure.

The process of differentiation implies that there will be different minerals or materials found on the surface and deeper in compared to the asteroids that were called rubble piles (non-differentiated).

So after an impact resulting in ejecta some of these samples are found on Earth as meteorites.

 

You're confused here. Asteroid families are thought to be results of past collisions and that's why they share almost the same orbital elements. There is no surprise that those would be very close in isotopic composition since at some stage most of them would've been a part of the same object.

 

Think of a scale first - the main asteroid belt extends from some 200 to some 700 million kilometers from the Sun and also quite a distance above and below the plane of ecliptic. This is an enormous volume and there's no currently known mechanism that would provide good mixing of all the initial material. As a result all the irregularities that would have been present in the giant gas cloud that came to become Solar system, would be represented in the composition of asteroids.

[Robittybob1]

 

You're confused here. Asteroid families are thought to be results of past collisions and that's why they share almost the same orbital elements. There is no surprise that those would be very close in isotopic composition since at some stage most of them would've been a part of the same object.

 

Think of a scale first - the main asteroid belt extends from some 200 to some 700 million kilometers from the Sun and also quite a distance above and below the plane of ecliptic. This is an enormous volume and there's no currently known mechanism that would provide good mixing of all the initial material. As a result all the irregularities that would have been present in the giant gas cloud that came to become Solar system, would be represented in the composition of asteroids.

Thanks. I did feel a little confused but I felt it was a "which comes first the chicken or the egg" situation. If NASA says they (the asteroid belts) are areas where planets form but other references say they are regions where protoplanets have broken up, which happens first? So that seems to be two opposing concepts and I considered that the protoplanet has to form first before it can be broken up.

[pavelcherepan]

 

 

If NASA says they (the asteroid belts) are areas where planets form

 

That's what your source says:

 

 

 

Asteroids are chunks of rock from "failed" planets, which never managed to coalesce into full-sized planets.

 

It doesn't say that planets form in asteroid belts. Main asteroid belt is in it's current state because Jupiter's (mostly) gravitational influence prevents material from coalescing into larger objects.

Edited February 8, 2016 by pavelcherepan

[Robittybob1]

 

That's what your source says:

 

 

It doesn't say that planets form in asteroid belts. Main asteroid belt is in it's current state because Jupiter's (mostly) gravitational influence prevents material from coalescing into larger objects.

I'll quote it again "Asteroids are chunks of rock from "failed" planets, which never managed to coalesce into full-sized planets. Asteroid belts can be thought of as construction sites that accompany the building of rocky planets." What is one to take from that?

"construction sites that accompany the building of rocky planets" could be taken several ways I suppose, but it is rather different to "destruction sites that accompany the demolition of rocky protoplanets" which seems to be the meaning you seem to favor.

"Failed" to me does not only imply destruction but also not fully formed as in "failed to fully form".

www.nasa.gov/multimedia/imagegallery/image_feature_1651.html

Edited February 8, 2016 by Robittybob1

[pavelcherepan]

 

 

but it is rather different to "destruction sites that accompany the demolition of rocky protoplanets" which seems to be the meaning you seem to favor.

 

Read my posts carefully. I've never said that. Stop making straw men.

[Robittybob1]

 

Read my posts carefully. I've never said that. Stop making straw men.

... and I never said you did. I was asking about the meaning? that is what I'm asking.

This is what you said earlier "Asteroid families are thought to be results of past collisions and that's why they share almost the same orbital elements. There is no surprise that those would be very close in isotopic composition since at some stage most of them would've been a part of the same object." That to me means you seem accept that they were once a protoplanet smashed by a collision back into asteroid components.

 

That is just my impression of what you said.

Edited February 8, 2016 by Robittybob1

[pavelcherepan]

I will quote my earlier post, because you don't seem to read them carefully:

 

 

 

Main asteroid belt is in it's current state because Jupiter's (mostly) gravitational influence prevents material from coalescing into larger objects.

 

What that means is that it was not because of collisions that a planet failed to form where asteroid belt is nowadays, but because Jupiter (and Saturn too) did disrupt it gravitationally and still do now. An object too large will interact strongly with the giant planet and will be kicked out of its orbit. That fate has come to many a planet embryo during early SS days before Jupiter and Saturn achieved their current orbital resonance as described in the Nice model.

[Robittybob1]

I will quote my earlier post, because you don't seem to read them carefully:

 

 

What that means is that it was not because of collisions that a planet failed to form where asteroid belt is nowadays, but because Jupiter (and Saturn too) did disrupt it gravitationally and still do now. An object too large will interact strongly with the giant planet and will be kicked out of its orbit. That fate has come to many a planet embryo during early SS days before Jupiter and Saturn achieved their current orbital resonance as described in the Nice model.

OK, you have made that clear. I will not comment till I hear from the Mods as to whether I'm allowed to discuss my ideas freely.

[swansont]

OK, you have made that clear. I will not comment till I hear from the Mods as to whether I'm allowed to discuss my ideas freely.

Do you have a model, or have evidence to match with predictions?

[Robittybob1]

Do you have a model, or have evidence to match with predictions?

Yes I think I do have a model. Evidence is not always that easy to find but I always try. There were predictions.

OK they are my own ideas and I would probably struggle to match those of the Nice Model for complexity but they are original and explain things in a way that fits fairly well.

Ophiolite has not always agreed for we have argued the point on other forums, but these discussions improve the model if anything. Nothing is set in concrete for it is continuing to develop.

The Nice model has been modified to the Nice II model, and that is to be expected, so please don't expect a diamond from me.

The math of the situation is very difficult for a person on his own like myself. If you keep asking for maths that becomes impossible.

[pavelcherepan]

 

The math of the situation is very difficult for a person on his own like myself. If you keep asking for maths that becomes impossible.

 

OK, no maths for now. In a few points can describe what your model explains and what it predicts? I've been discussing with you for ages and I still have no idea what your model is.

Edited February 8, 2016 by pavelcherepan

[Robittybob1]

 

OK, no maths for now. In a few points can describe what your model explains and what it predicts? I've been discussing with you for ages and I still have no idea what your model is.

Have you been discussing with me at other sites as well as here? I have been relatively quiet while I'm here so that might explain it.

It will need the moderator OK for I hate those warning points, as I'm reminded of them every time I come here.

[pavelcherepan]

I believe swansont told you that you can post as long as you have some model that makes predictions that match observations.

[Robittybob1]

I believe swansont told you that you can post as long as you have some model that makes predictions that match observations.

I have had a clear answer by PM (thanks). Swansont was just asking a question AFAIK. I'll still have to fully understand what I'm letting myself in for I take it really seriously and it takes a lot of emotional energy to argue a new idea. I appreciate your interaction but I'm going to need to be careful, twice I've read one particular word incorrectly, maybe it is your style ("would've" ??) but it is more likely a fault of my own. I have not got over the other day yet.

"How could this be tested to ensure that it's true?" That is the essential part from the forum rules on discussing in Speculations.

 

We will always have the chance of seeing the same thing happen in a Hubble photo or some other image. If we can see the same thing happening in the Universe is that a sufficient test that it is true, even if the actual image is not known? If it has the potential to be found sometime in the future?

Einstein's prediction was like this in that proof that mass bent light had to wait for the next two solar eclipses to happen before photos of the event were taken and the prediction confirmed.

I feel I'm in the same situation in that I have a speculation that has some evidence but not the definitive proof. How could I ever get a photo of an asteroid belt being formed? How will I ever be able to recognize it?

 

Thinking about it that means it always has the potential to be verified, but I don't want it to be argued if that was the case any astronomical event can be speculated for who knows what could be seen somewhere in the Universe sometime in the future. [i haven't needed to refer to possible multiverses either as yet and I won't do that.]

Edited February 8, 2016 by Robittybob1

[pavelcherepan]

 

We will always have the chance of seeing the same thing happen in a Hubble photo or some other image. If we can see the same thing happening in the Universe is that a sufficient test that it is true, even if the actual image is not known? If it has the potential to be found sometime in the future?

Einstein's prediction was like this in that proof that mass bent light had to wait for the next two solar eclipses to happen before photos of the event were taken and the prediction confirmed.

I feel I'm in the same situation in that I have a speculation that has some evidence but not the definitive proof. How could I ever get a photo of an asteroid belt being formed? How will I ever be able to recognize it?

 

It's the whole purpose of predictions. you're not meant to have them observed immediately. A theory needs to predict some new effects, and normally predictions are done via mathematical framework. On the other hand, if you say you have a theory and you don't want to do maths, no one will take you seriously.

 

 

 

maybe it is your style ("would've" ??)

 

It's a standard form of contraction in English - would+have = would've. I assure you, it's not just my style.

[Robittybob1]

Well there is another problem for if I say I predict that inner planets are formed before the star goes thermonuclear, there may never be enough light to produce this image.

The other prediction was that the intense wind from a star going thermonuclear was the primary reason a planet in the asteroid belt stage of its development is unlikely to complete the planet building process, it will fail, so it will end up like the Asteroid Belt.

 

Another prediction, which has now been discovered, was that there will be water world planets close in to their stars.

That this volatile mass will later be transported further out in the protoplanetary disc to areas where planets are yet to form. (That loss of volatiles is gaining credence as they study Mars currently).

Planets may still be forming further out in the star system (in our Solar System for example). There was talk recently of another large planet being predicted.

 

The water world sized terrestrial planet can allow for moon captures. (We tried to argue this the other day).

As the mass of volatiles can far exceed the terrestrial mass the rocky part is compressed and rebounds as the volatile mass is transported. (Is a version of this being argued by Arc in his thread?)

 

As you can see it would be an enormous task to handle all those speculations and some more without a doubt. I will do it but it will need to wait for there are some important issues to deal with first of all.

You might wonder why I have tackled so many strange speculations but one becomes a priory of the other for I think most will appreciate a water world won't form near a star during its main sequence phase.

It maybe now more accepted that inner planets form prior to the thermonuclear stages, I'm not totally up to date on that for it has been a few years since it was first proposed.

So we then get inner planets that are more suited to the formation of living organisms etc but that also means planets further out are less suitable as they are relatively cold.

So I do tend to the philosophy of panspermia at least within the Solar System.

Does the compressed Earth still allow for plate tectonics? Does it allow for the Moon formation or capture?

Does the transfer of mass from the inner planets account for the size of the Gas and Ice Giant planets?

How do these giant planets capture the mass as it is being transferred?

 

I tell you honestly there are some difficult questions to answer if these speculations are going to hold.

Edited February 8, 2016 by Robittybob1

[pavelcherepan]

I think your best bet would be to try and tackle all these ideas one by one, rather than piling them up like that.

 

If you take one of your ideas, do a proper research, find evidence to support it and structure it well in your head, we could have some interesting discussions. But as things stand now and based on past experience I'm pretty sure I won't see any proof of your ideas and so any discussion is pointless.

[Mordred]

As part of your research in regards to asteroid belts I would include density wave theory. Which does a good job in describing the rings of Saturn. As far as planetary formation. One major contributing factor is the density of materials. Much like a centrifuge different density materials will accumulate at a different radius. Heavier metals will typically accumulate closer to the sun. There is a certain range where water accumulation will commence depending on the mass of the star for similar reasons. (Without transport via comets etc).

[Robittybob1]

As part of your research in regards to asteroid belts I would include density wave theory. Which does a good job in describing the rings of Saturn. As far as planetary formation. One major contributing factor is the density of materials. Much like a centrifuge different density materials will accumulate at a different radius. Heavier metals will typically accumulate closer to the sun. There is a certain range where water accumulation will commence depending on the mass of the star for similar reasons. (Without transport via comets etc).

Thanks for the lead. I have not heard of the density wave theory before now.

I think your best bet would be to try and tackle all these ideas one by one, rather than piling them up like that.

 

If you take one of your ideas, do a proper research, find evidence to support it and structure it well in your head, we could have some interesting discussions. But as things stand now and based on past experience I'm pretty sure I won't see any proof of your ideas and so any discussion is pointless.

OK if you see any papers that might lend support to any of the above how about letting me know. I would think theories explaining how water worlds formed close to their star would be a good start.

Edited February 8, 2016 by Robittybob1