I keep hearing 4.6 to 4.7 billion years old for the age of the planet. Usually proved by dating meteorites. However, you never hear of anything older than this. Even though it [appears](https://world-nuclear.org/information-library/nuclear-fuel-cycle/uranium-resources/the-cosmic-origins-of-uranium.aspx) that the uranium that we use to date the planet was formed 6.5 billion years ago from the previous generation of stars.
The dust cloud that contained all the material that makes up both the planet and asteroids was here long before that.
So, my question is this, How did we settle on 4.6 – 4.7 billion years old for the age of the planet when all the materials were here long and coalescing before that? Did we just not cosider it a planet before the formation of the sun?
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Edited for corrections and clarity (hopefully). I can’t remove solar system from the subject line.
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A swirling cloud of dust and gas does not make a solar system. A solar system means there’s a star, which the cloud of gas and dust that would become our solar system was not a solar system until our sun initiated the process of nuclear fusion.
Think about it this way. If you have all of the building materials of a house (lumber, brick, concrete, glass…etc) is that a house? No, it’s not a house until it’s built.
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