Nebular hypothesis

The unequal distribution of angnlar momentnm between the planets and the sun remains an unsolved problem, bnt not considered serions enough to finally abandon the nebular hypothesis. Rival theories such as the disintegration of one of a binary pair of stars to form the planets also leave many questions unanswered and a qnantitatively correct model has not been formulated. However, after the time of Newton observational astronomy moved out of the solar system to examine the stars in the Milky Way, also known as the Galaxy, based on the Greek word for milk. 

Lambert, Johann Heinrich (1728-1777) Swiss-born mathematician, physicist and astronomer in Augsburg and Berlin he studied hght intensity and also developed a theory of the generation of the universe that was similar to the nebular hypothesis that Thomas Wright and Immanuel Kant had (independently) developed. 

It is also possible that neither of these mechanisms for providing water to the inner planets is correct. Another hypothesis is that absorption of water onto dust particles in the accretion disk might account for the Earth s oceans (Drake, 2005). As already mentioned, the amount of water required to explain Earth s water is not large on a per-gram basis. Regardless of whether comets, asteroids, or nebular particles were the source of our planet s oceans, the water likely came from more distant regions of the nebular disk. 

In summary, it appears from Figure 17 that the bulk composition of the Earth is related to the carbonaceous chondrites, suggesting the same event of manganese depletion for carbonaceous chondrites and the Earth. This supports the hypothesis that the depletion of volatile elements in the various solar system materials is a nebular event at the beginning of formation of the solar system as suggested by Palme et al. (1988), Humayun and Cassen (2000), and Nyquist et al. (2001). 

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