Earth's Oldest Known Rock Was Found On the Moon (popularmechanics.com) 28
schwit1 quotes Popular Mechanics: A lot of the rocks we have on Earth are pretty old, but none of them were around when our planet was first formed. The Earth itself is around 4.5 billion years old, and the oldest rocks we've ever found are a little over half that age. That seems to have changed, however, because a group of scientists recently announced they've found a rock that formed only half a billion years after the Earth itself. The twist is that this particular rock wasn't discovered on Earth at all. It was found on the moon.
The rock itself was discovered decades ago by the Apollo 14 crew. The Apollo missions brought back a whole lot of rock samples, and scientists have been methodically analyzing them ever since. This one seems to have been somewhere near the end of the list, but it may be the most interesting one ever found.
According to the analysis, this rock formed somewhere between 4 and 4.1 billion years ago, about 12.4 miles beneath the Earth's crust. Researchers knew it came from the Earth based on the amount of various minerals like quartz and feldspar, which are common on Earth but rare on the Moon. They could tell how deep it was based on a molecular analysis of the rock, which can tell the researchers what temperature the rock was at when it formed.
The rock itself was discovered decades ago by the Apollo 14 crew. The Apollo missions brought back a whole lot of rock samples, and scientists have been methodically analyzing them ever since. This one seems to have been somewhere near the end of the list, but it may be the most interesting one ever found.
According to the analysis, this rock formed somewhere between 4 and 4.1 billion years ago, about 12.4 miles beneath the Earth's crust. Researchers knew it came from the Earth based on the amount of various minerals like quartz and feldspar, which are common on Earth but rare on the Moon. They could tell how deep it was based on a molecular analysis of the rock, which can tell the researchers what temperature the rock was at when it formed.
where/when (Score:1)
So the moon is about 4.5b years old. The rock is 4.1b years old. Surely by that stage the earth had re-solidified enough after the moon forming impact that an impact large enough to blow stuff into space would be noticeable as far as deformation. Any ideas where/when this impact actually happened?
Re: (Score:2, Insightful)
impact large enough to blow stuff into space would be noticeable as far as deformation
Do you mean we should still be able to see it after 4.1 billion years? We almost couldn't find the Chicxulub crater from 65 million years ago, and you think we should be able to find a crater from 4.1 billion years ago?
Re: (Score:3)
Perhaps PP was referring to deformation within the rock itself. Shocked quartz is evidence of meteorite impacts. And it has been found in core samples around Chicxulub.
Lucky that the Apollo mission found this one lying on the surface.
Re: (Score:2)
Moon rocks are occasionally found on Earth, as are Mars rocks. I wonder if any Venus rocks have been found?
Re: (Score:2)
It is a Mars rock. The controversy was about whether it contained sufficient evidence of fossilized microbes. The jury is still out on that, by the way.
Re: (Score:2)
Pro tip: there is vastly more to the internet than the entertainment site Inforwars. You know, like facts and sh1t.
Wikipedia seems to have been duped too [wikipedia.org]
Oldest rock (Score:2)
Keith Richards?
Another first. (Score:2)
Re: (Score:2)
And is missing any concept of imagination.