Question Earth Moon Origin

[Catastrophe]

Billslugg, some of these might interest you:

gaia collision video - Bing

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www.bing.com

There is another somewhere I have mislaid. It shows diagrams at intervals like 1 minute, 10 minutes, 1 hour, 4 hours . . . . . . something like that.

Cat

 

[billslugg]

The galaxy video is mesmerizing. The interaction really tore the tiny galaxy to shreds. First it makes it a needle then a cloud. Very interesting.

 

[Catastrophe]

If you put balloons on the surface of the pool water and pull the plug they will simply gather together in the center. If they pool is big enough, say hundreds of miles across, and is not located on the equator, then the Coriolis force will result in the bunch of balloons rotating. The amount of angular momentum of any such gathering is proportional to its area. A small knot within a large assemblage will have only a tiny angular momentum, not sufficient to explain the Moon's. This pretty much rules out coformation from dust knots. It leaves collision or capture. Collision is far more likely as there are many spots on Earth where a good hit would make a Moon. There are not a lot of spots the Moon and a third body could do a dance resulting in the capture of the Moon. Collision requires two bodies, somewhat rare. Capture requires three bodies, extremely rare. Also, the Moon crust and Earth crust are identical. This rules out capture. Collision is the only one that can account for all the data. There are still some nagging details they can't figure out.

Billslugg

There are still some nagging details they can't figure out.

Are you now happy with the 1%/13% "problem"?

Cat

 

[Inmymind]

I had not seen that one, it is really detailed. It gives two bodies, one of which falls back to Earth, the other stays out there to become the Moon. What is very evident is that the outcome is extremely dependent on the offset between the two bodies. This means that the impact scenario is flexible, can account for most any observation today simply by changing where it hit.
I would like to see a similar movie showing how an accretion scenario might work out.

"I would like to see a similar movie showing how an accretion scenario might work out"

Me too, but I wonder how many movies could be modelled to fit the "facts" in any current scenario.
I am hopeful that as more data comes in more refined modelling will emerge.

 

[billslugg]

All you need to do is show one plausible way of forming the Moon by impact to keep the impact theory alive.

 

[Inmymind]

All you need to do is show one plausible way of forming the Moon by impact to keep the impact theory alive.

Science will move in the direction of more accurate reflection

 

[Harry Costas]

When the solar system formed from our Sun, releasing its solar envelope or going through a Nebulae or a combination.

The resultant effect is CHAOS. From Chaos, objects that did not dance together collided with each other or the Sun.

The Objects that stayed together had uniform orbital motion.

The rocks between Mars and Jupiter form a uniform ring, suggesting that our Sun's Core formed dipolar vector fields forming an hourglass image expelling matter from our Sun into the Solar System.
The inner planets have Iron core properties the outer regions form ice objects.
Sun's Gravity held back the heavier objects.

Well, the evidence for any theory has not come to nest.
The cows will come home one day.
The chickens have not laid their eggs.

 

[Harry Costas]

Oring of moon??

"". The identical nucleosynthetic (O, Cr, Ti) and radiogenic (W) isotope compositions of the lunar and terrestrial mantles, strongly suggest the two bodies were made from the same material, rather than from an Earth-like impactor. Rb-Sr in FANs and Lu-Hf and Pb-Pb zircon ages point Moon formation close to ∼4500 Ma. Taken together, there is no unambiguous geochemical or isotopic evidence for the role of an impactor in the formation of the Moon, implying perfect equilibration between the proto-Earth and Moon-forming material or alternative scenarios for its genesis.""

[2408.16840] Composition, Structure and Origin of the Moon

 

[Harry Costas]

Step by step we are understanding the evolution of our Solar System.
Baby Steps

[Submitted on 23 Apr 2024]

The Solar System: structural overview, origins and evolution​

Sean N. Raymond

Understanding the origin and long-term evolution of the Solar System is a fundamental goal of planetary science and astrophysics. This chapter describes our current understanding of the key processes that shaped our planetary system, informed by empirical data such as meteorite measurements, observations of planet-forming disks around other stars, and exoplanets, and nourished by theoretical modeling and laboratory experiments. The processes at play range in size from microns to gas giants, and mostly took place within the gaseous planet-forming disk through the growth of mountain-sized planetesimals and Moon- to Mars-sized planetary embryos. A fundamental shift in our understanding came when it was realized (thanks to advances in exoplanet science) that the giant planets' orbits likely underwent large radial shifts during their early evolution, through gas- or planetesimal-driven migration and dynamical instability. The characteristics of the rocky planets (including Earth) were forged during this early dynamic phase. Our Solar System is currently middle-aged, and we can use astrophysical tools to forecast its demise in the distant future.

 

[Harry Costas]

Origin of the moon.

[Submitted on 29 Aug 2024]

Composition, Structure and Origin of the Moon​

Paolo A. Sossi, Miki Nakajima, Amir Khan

Here we critically examine the geophysical and geochemical properties of the Moon in order to identify the extent to which dynamical scenarios satisfy these observations. New joint inversions of existing lunar geophysical data (mean mass, moment of inertia, and tidal response) assuming a laterally- and vertically homogeneous lunar mantle show that, in all cases, a core with a radius of 300±20 km (∼0.8 to 1.5 % the mass of the Moon) is required. However, an Earth-like Mg# (0.89) in the lunar mantle results in core densities (7800±100 kg/m3) consistent with that of Fe-Ni alloy, whereas FeO-rich compositions (Mg# = 0.80--0.84) require lower densities (6100±800 kg/m3). Geochemically, we use new data on mare basalts to reassess the bulk composition of the Moon for 70 elements, and show that the lunar core likely formed near 5 GPa, 2100 K and ∼1 log unit below the iron-wüstite buffer. Moreover, the Moon is depleted relative to the Earth's mantle in elements with volatilities higher than that of Li, with this volatile loss likely having occurred at low temperatures (1400±100 K), consistent with mass-dependent stable isotope fractionation of moderately volatile elements (e.g., Zn, K, Rb). The identical nucleosynthetic (O, Cr, Ti) and radiogenic (W) isotope compositions of the lunar and terrestrial mantles, strongly suggest the two bodies were made from the same material, rather than from an Earth-like impactor. Rb-Sr in FANs and Lu-Hf and Pb-Pb zircon ages point Moon formation close to ∼4500 Ma. Taken together, there is no unambiguous geochemical or isotopic evidence for the role of an impactor in the formation of the Moon, implying perfect equilibration between the proto-Earth and Moon-forming material or alternative scenarios for its genesis.