Mercury Impactor

[Dominatus]

The planet mercury is little more than an iron core. We think this is due to a large impact with another planet in the past. What I can't seem to figure out is what happened to the planet mercury collided with.

Was it perhaps a young earth, and this resulted in the formation of our moon? Did this planet go on to become Venus? Mars? Was it ejected from the solar system completely? I can't seem to find any information on this beyond the articles talking about the hit and run collision mercury was involved in.

And as a bit of a side note, I have discovered my interests are in the fields of planetary formation and long-term gravitational interactions in our solar system and in others... What career would allow me to pursue this interest best?

Thanks!

[Dkmdlb]

And as a bit of a side note, I have discovered my interests are in the fields of planetary formation and long-term gravitational interactions in our solar system and in others... What career would allow me to pursue this interest best?

Long term unemployment?

[Dominatus]

Note: did some research, apparently scientists seem to think that mercury glanced either Venus or earth several times. Which begs the question; which of the two planets is more likely; earth, because of the moon left over as a relic from an impact with a body the size of mars? Or Venus, whose cloud cover might obscure the geologic scars following such an event? One way I think we could get more accurate estimates on this is to figure out how large mercury was prior to impact... Possibly by finding the average core:radius ratio in the observed solar system, allowing for an estimate of the size mercury used to be based on how large it's core is. Ie, one would expect that the cooled core of mars would compare in equal size to that of mercury, assuming mercury was the mars-sized impact which was responsible for the formation of our moon...

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More research.. The Martian core has a radius of 1,794km +- 65km to a planetary total radius of 3,390km

Mercury's core has a radius of 1,800km to a planetary radius of 2,440km. The Earth's core has two measurements; the solid inner core has a radius of 1,220km, but if the liquid outer core is counted than it measures at radius 3,400km to a planetary radius of 3,390km. Density comes into play here, obviously.. However, I wager that density might be a relic from planetary formation, and would not have anything to do with calculating the previous size of mercury. Thoughts, anyone? Am I even on the right track here or wasting my time?

Edit: I realize some of these calculations make no sense. Please keep in mind multiple sources contributed to this information, and they have been complied here. There are some glaring inaccuracies (especially about the earths cot radius being 100km larger than the earth's actual radius). Correct as you see fit.

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"To better understand what might have happened Asphaug and Reufer ran computer simulations that showed a proto-Mercury colliding with various sized planets at various speeds and angles. They found that if a planet about the size of modern Earth collided with proto-Mercury at just the right angle and speed, it would have been possible for proto-Mercury to lose a large portion of its mantle due to it being stripped away. Furthermore, they noted that such an impact would not result in the proto-Mercury being caught in the larger planet's gravity, effectively turning it into a moon. Such a collision, they also note would have resulted in much of the material ejected into space falling back to the target body, resulting in it being more metal rich than before the impact." - http://m.phys.org/news/2014-07-simulations-mercury-victim-hit-and-run-collision.html

So, an earth sized object, huh? This is starting to seem much more likely.

Venus could also have played a role in this, slowing mercury down in subsequent orbits with it's gravitational well? Of course that is purely conjecture.

Edited January 13, 2015 by Dominatus

[Dominatus]

Look, I would really appreciate collaboration here with other people who are more knowledgeable than I am, especially concerning astrophysics like this. I would really like to discuss this topic and try to figure out if this is just a coincidence or if the fabled planet Theia was in fact an early mercury. My data is off,

I realize that, but that is the result when you obtain the measurements from three different sources. Anyone who can contribute to this discussion? Even if it's to tell me I'm off my rocker?

[Bill Phil]

The orbit is so off it probably would t be an early Theia. Maybe the Moon got captured without a massive collision. I think there was a theory where a large amount of debris stripped Mercury of its mantle, hitting Venus and reversing it's rotation, and finally hitting Earth and creating the moon.

[*Aqua*]

Scientist believe the Moon is made out of the leftovers of a Mars-sized planet ("Theia") and the Proto-Earth. Why they think that? Earth has way more heavy elements than Venus despite being only slightly larger. And the surface materials of Moon and Earth are very alike pointing to a common origin.

I think Mercury is so heavy because the sun blew nearly all lighter elements into the outer parts of the solar system. This would explain why the inner planets are rocky and the outer ones are gas giants.

[Dominatus]

That's true but it still doesn't explain what happened to the Impactor that stripped mercury of it's mantle and glanced the earth to create the moon... I mean maybe they were ejected from the solar system?

[Bill Phil]

Maybe the Moon and the Mercury Event aren't even related. Space is big. It's possible that it entered into a century long orbit, or maybe a 65 million year long orbit. Massive extinction theory, anyone? Nah...

[-Velocity-]

The planet mercury is little more than an iron core. We think this is due to a large impact with another planet in the past. What I can't seem to figure out is what happened to the planet mercury collided with.

Was it perhaps a young earth, and this resulted in the formation of our moon? Did this planet go on to become Venus? Mars? Was it ejected from the solar system completely? I can't seem to find any information on this beyond the articles talking about the hit and run collision mercury was involved in.

Astronomers have believed for decades that the early solar system was a much more crowded place. There may have been like, 7, 8, 10 large inner planets- who knows, maybe more- right after the main phase of planetary accretion was complete. The four inner planets left today are just the survivors in a game of gravitational billiards. If Mercury DID survive a giant impact that blasted off much of its mantle, then the debris that escaped Mercury's influence was most likely ejected from the solar system or impacted other objects. Who knows, maybe some of it is still around in the form of a few small asteroids.

Anyway, the point is, to think there's some connection between the object that purportedly hit Earth to form the Moon ("Theia"), and an object that possibly might have hit Mercury, is not logical.

Edited January 14, 2015 by |Velocity|

[Dominatus]

The hypothesis is, admittedly, tentative at best. However, the likelihood that mercury impacted an earth-sized object and glanced it, and a mars-sized object glanced the earth... It's a strange coincidence. And is possible. I realize that the early solar system was crowded, with as many as 20 bodies. But many of these were either accreted into the ones left today or else scraped by with minor damage, ie mercury. We don't have surface samples yet so obviously we cannot confirm any relation between the surface composition of mercury and that of the moon. Even so, I don't believe that point alone is enough to discredit this. At the very least we should attempt to use the scientific data at our disposal to disprove this hypothesis beyond a shadow of a doubt. If we simply dismissed something as unlikely and didn't pursue it further, the scientific world would be seriously lacking some important, fundamental ideas. Keplers 3 laws of planetary motion anyone?

Edited January 15, 2015 by Dominatus