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Isn't it kind of weird to use the Moon to benchmark the age of the solar system when it's well known that the Moon formed after another body collided with the E
by politician 5y ago
Isn't it kind of weird to use the Moon to benchmark the age of the solar system when it's well known that the Moon formed after another body collided with the Earth? The Moon is younger than the Earth.
- tshaddox 5y agoI assume it’s because the Moon is geologically inactive and thus the rocks we got from the surface are expected to be essentially as old as the Moon itself.
- pdonis 5y agoNot to benchmark, precisely, but to give a lower limit on the age that will likely be longer than any other lower limit we could obtain at our current or near future level of technology.
- vlovich123 5y agoIf Theia is older than the Earth, then wouldn't the Moon also be older?
- politician 5y agoAIUI, the heat of the collision would've melted everything that wasn't already molten. Any "age" information would be lost as the system cooled. At least, that's my understanding from playing with Universe Sandbox.
- vlovich123 5y agoThat would only be the case for the piece that collided though right? The side that wasn’t part of the collision should have retained its age information. Also, presumably Theia didn’t bounce off but just merged with the moon being formed from the piece of Earth on the opposite side from the collision that got ejected, right? So at most half the moon surface should be from the collision and half of it should have the age of the Earth?
- treeman79 5y agoMoon is a mix of earth and theia. So is Earth. So sort of like a strawberry banana smoothie in two cups. Core of Theia sunk into Earth and there is some recent imaging showing what may be the second core. https://www.iflscience.com/environment/fragments-of-the-planet-that-formed-the-moon-may-be-buried-by-the-earths-core/ https://www.iflscience.com/environment/fragments-of-the-plan...
- jacquesm 5y agoTheia is - for now - a hypothesis, not an established fact.