<p>Mercury has an unusual composition: It seems to consist mostly of metal, which is otherwise common in the cores of planets. Also, Mercury's rocks are rich in volatile materials, which could not have formed as near to the Sun as Mercury is today (cf. <a href="https://www.ldeo.columbia.edu/news-events/messenger-data-reveals-evidence-ancient-carbon-rich-crust-mercury" rel="nofollow noreferrer">https://www.ldeo.columbia.edu/news-events/messenger-data-reveals-evidence-ancient-carbon-rich-crust-mercury</a>). Therefore, astronomers have conjectured that some cataclysmic event (eg. a collision) might have thrown Mercury closer to the Sun and ripped off most of its crust.</p>
<p>Now the question is: What became of the crust? And since the asteroid belt is not very rich in metal (or is it? Did I misunderstand?), I wonder whether its origin might have been said collision (probably with Mars, or possibly with Ceres).</p>
<p>Also, the asteroid belt is rather carbon-rich, just like the remnant of Mercury's crust (<a href="https://progearthplanetsci.springeropen.com/articles/10.1186/s40645-019-0312-z" rel="nofollow noreferrer">https://progearthplanetsci.springeropen.com/articles/10.1186/s40645-019-0312-z</a>). Coincidence?</p>
<p>Perhaps, one could even make sense of it from a physical perspective: Crust and mantle might have &quot;repelled&quot; each other, that is, by Newton's principle of contrary motion, the two would have travelled in different directions, Mercury inwards and the debree outwards. (EDIT: To clarify this point: An object might have hit primordial Mercury, causing its crust to separate from what's now Mercury, so the crust may have first pushed Mercury, and then seperated and went off in the opposite direction.)</p>
<p>Also, the mass of the asteroid belt is little enough so that all could have come from Mercury's former crust. Indeed, it totals roughly twice the mass of Pluto's moon Charon.</p>

CC BY-SA 4.0
2021-07-31T03:05:04.387Z
*Crust and mantle might have repelled each other*  Why would they repell each other ?
StephenG - Help Ukraine
CC BY-SA 4.0
2021-07-31T09:35:55.883Z
@StephenG Of course, the motion would have been initiated by the object primordial Mercury may have collided with.
AlgebraicsAnonymous
CC BY-SA 4.0
2021-07-31T09:47:37.687Z
@uhoh In case you are unable to manage to google it yourself: Here is one of the returns of a search for "messenger mission mercury volatile sulphur formation": https://www.ldeo.columbia.edu/news-events/messenger-data-reveals-evidence-ancient-carbon-rich-crust-mercury This is, by now, a standard fact in astronomy.
AlgebraicsAnonymous
CC BY-SA 4.0
2021-07-31T09:49:24.570Z
It additionally speaks of a "carbon-rich crust", and guess which material is abundant in the asteroid belt...
AlgebraicsAnonymous
CC BY-SA 4.0
2021-07-31T11:02:02.950Z
See also: https://progearthplanetsci.springeropen.com/articles/10.1186/s40645-019-0312-z
AlgebraicsAnonymous
CC BY-SA 4.0
2021-07-31T14:23:20.490Z
@AlgebraicsAnonymous questions should support their premises with facts supported by citing sources. Whether I know something not, we shouldn't expect every reader to go google things after reading each question. It would be better if you added a few sentences to your question citing those sources for the benefit of all readers, many folks don't go through all the comments before deciding how they are going to vote. *Thanks!*
uhoh
CC BY-SA 4.0
2021-07-31T14:32:34.867Z
@uhoh I appreciate your more considerate tone. I'll be considering in turn whether to edit my question, even though I've spent a lifetime being taunted, whence the downvote doesn't bother me too much.
AlgebraicsAnonymous
CC BY-SA 4.0
2021-07-31T15:07:51.683Z
@AlgebraicsAnonymous every Stack Exchange site is a bit like like a different country or at least different culture. Astronomy and Space Exploration are popular topics and so those SE sites get a wide range of questions by a wide range of people; In order to accommodate that it's become standard to often ask for "evidence of prior research" and/or premise support, otherwise a lot of unsupportable questions start appearing. Those links are fascinating! I think the make an excellent basis for your question!
uhoh
CC BY-SA 4.0
2021-07-31T16:17:55.400Z
If Mercury collided with Mars or Ceres probably both worlds would have been totally shattered to red hot pieces.
M. A. Golding
CC BY-SA 4.0
2021-07-31T19:50:35.087Z
@M.A.Golding But isn't the moon supposed to have originated from a collision of the Earth and another object? And Earth still stands.
AlgebraicsAnonymous
CC BY-SA 4.0
2021-07-31T19:51:33.927Z
@uhoh I modified the post, yet the vote count seems to remain at -1...
AlgebraicsAnonymous
CC BY-SA 4.0
2021-07-31T20:56:59.233Z
@AlgebraicsAnonymous I've deleted my comment and added a +1 to the existing -1.  Astronomy SE moves a little more slowly than many other sites, give it some time.
uhoh
CC BY-SA 4.0
2021-08-01T02:03:37.520Z
["at least 85 percent of 200,000 asteroids in the inner asteroid belt — the main source of Earth’s meteorites — originate from five or six ancient minor planets. The other 15 percent may also trace their origins to the same group of primordial bodies"](https://news.ufl.edu/articles/2018/06/study-reveals-secret-origins-of-asteroids-and-meteorites.html)
Keith McClary
CC BY-SA 4.0
2021-08-01T11:01:46.260Z
But then the number 5-6 was arrived at by comparing the different materials and their relative abundance inside the asteroid belt, and then making the assumption that the 5-6 bodies were completely shattered into pieces. But suppose a big core (like today's Mercury) was left over from the collision. Then the lower metal concentration would still be plausible. @KeithMcClary
AlgebraicsAnonymous
<mercury><asteroid-belt>
Is the asteroid belt made up of Mercury's former crust?
AlgebraicsAnonymous
# Is the asteroid belt made up of Mercury's former crust?

(Asked by: username_0 on 2021-07-30)

Mercury has an unusual composition: It seems to consist mostly of metal, which is otherwise common in the cores of planets. Also, Mercury's rocks are rich in volatile materials, which could not have formed as near to the Sun as Mercury is today (cf. <https://www.ldeo.columbia.edu/news-events/messenger-data-reveals-evidence-ancient-carbon-rich-crust-mercury>). Therefore, astronomers have conjectured that some cataclysmic event (eg. a collision) might have thrown Mercury closer to the Sun and ripped off most of its crust.

Now the question is: What became of the crust? And since the asteroid belt is not very rich in metal (or is it? Did I misunderstand?), I wonder whether its origin might have been said collision (probably with Mars, or possibly with Ceres).

Also, the asteroid belt is rather carbon-rich, just like the remnant of Mercury's crust (<https://progearthplanetsci.springeropen.com/articles/10.1186/s40645-019-0312-z>). Coincidence?

Perhaps, one could even make sense of it from a physical perspective: Crust and mantle might have "repelled" each other, that is, by Newton's principle of contrary motion, the two would have travelled in different directions, Mercury inwards and the debree outwards. (EDIT: To clarify this point: An object might have hit primordial Mercury, causing its crust to separate from what's now Mercury, so the crust may have first pushed Mercury, and then seperated and went off in the opposite direction.)

Also, the mass of the asteroid belt is little enough so that all could have come from Mercury's former crust. Indeed, it totals roughly twice the mass of Pluto's moon Charon.

**Tags:** mercury, asteroid-belt

> **Comments:**
> **username_1**: *Crust and mantle might have repelled each other*  Why would they repell each other ?  
> **username_0**: @username_1 Of course, the motion would have been initiated by the object primordial Mercury may have collided with.  
> **username_0**: @username_2 In case you are unable to manage to google it yourself: Here is one of the returns of a search for "messenger mission mercury volatile sulphur formation": https://www.ldeo.columbia.edu/news-events/messenger-data-reveals-evidence-ancient-carbon-rich-crust-mercury This is, by now, a standard fact in astronomy.  
> **username_0**: It additionally speaks of a "carbon-rich crust", and guess which material is abundant in the asteroid belt...  
> **username_0**: See also: https://progearthplanetsci.springeropen.com/articles/10.1186/s40645-019-0312-z  
> **username_2**: @username_0 questions should support their premises with facts supported by citing sources. Whether I know something not, we shouldn't expect every reader to go google things after reading each question. It would be better if you added a few sentences to your question citing those sources for the benefit of all readers, many folks don't go through all the comments before deciding how they are going to vote. *Thanks!*  
> **username_0**: @username_2 I appreciate your more considerate tone. I'll be considering in turn whether to edit my question, even though I've spent a lifetime being taunted, whence the downvote doesn't bother me too much.  
> **username_2**: @username_0 every Stack Exchange site is a bit like like a different country or at least different culture. Astronomy and Space Exploration are popular topics and so those SE sites get a wide range of questions by a wide range of people; In order to accommodate that it's become standard to often ask for "evidence of prior research" and/or premise support, otherwise a lot of unsupportable questions start appearing. Those links are fascinating! I think the make an excellent basis for your question!  
> **username_3**: If Mercury collided with Mars or Ceres probably both worlds would have been totally shattered to red hot pieces.  
> **username_0**: @username_3 But isn't the moon supposed to have originated from a collision of the Earth and another object? And Earth still stands.  
> **username_0**: @username_2 I modified the post, yet the vote count seems to remain at -1...  
> **username_2**: @username_0 I've deleted my comment and added a +1 to the existing -1.  Astronomy SE moves a little more slowly than many other sites, give it some time.  
> **username_4**: ["at least 85 percent of 200,000 asteroids in the inner asteroid belt — the main source of Earth’s meteorites — originate from five or six ancient minor planets. The other 15 percent may also trace their origins to the same group of primordial bodies"](https://news.ufl.edu/articles/2018/06/study-reveals-secret-origins-of-asteroids-and-meteorites.html)  
> **username_0**: But then the number 5-6 was arrived at by comparing the different materials and their relative abundance inside the asteroid belt, and then making the assumption that the 5-6 bodies were completely shattered into pieces. But suppose a big core (like today's Mercury) was left over from the collision. Then the lower metal concentration would still be plausible. @username_4  

---

## 0 answers

