Questions tagged [planetary-formation]

Questions about the processes, theories and evidence for the formation of planetary bodies, mostly the Earth.

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12
votes
3answers
6k views

Why is Earth's Core Iron?

The two major constituents of the Earth's core are iron and nickel. In documentaries and scientific conversations, iron gets more attention than nickel, probably because it makes up a bigger ...
36
votes
5answers
3k views

How do we know the asteroids formed at the same time as earth?

In continuation of the question Why is Earth's age given by dating meteorites rather than its own rocks?, what evidence do we have that the asteroids indeed formed at the same time as earth? Is there ...
5
votes
2answers
638 views

Were all of Earth's minerals created before Earth's formation, during, or after?

I've heard that during the accretion of proto-planets that formed the earth, 60 minerals were created through the reactions of atoms and molecules in the nebula. Do these first minerals still make up ...
3
votes
0answers
73 views

Endogenous Theories For the Origin of Earth's Water (Dry/Wet Accretion?)

I have really two questions: (1) what evidence is there in favour that the majority of Earth's water formed with the planet. (2) what evidence is there that the majority of water did not form with ...
1
vote
1answer
81 views

How can radiometric dating of meteorites determine the age of the earth? Wouldn't this only determine the age of the decaying nuclide in each rock? [duplicate]

How can the radiometric dating of different meteorites determine the age of the earth? Wouldn't radioactive decay have already been occurring in all of those meteorites long before they hit earth? ...