I still don't think anyone would think 2.5 billion years ago would be recent, on a body that is only 4.5 billion years old. 2.5 billion in the past is less than mid-point in the moon's age, closer to the beginning than the end.
To a planetary scientist who is familiar with lunar geology, yes that is recent. It was widely believed after Apollo that the lunar core shut off and plate tectonics stopped soon after formation. 2Gya is a long time from now, but it is also almost equidistant from lunar formation. So the title here ought to be “the Moon was geologically active for almost 2 billion years after formation” which IS surprising.
I'm not sure there's a consensus, I expect it depends on your astronomical area of study. If you study the whole universe, than our solar system at 4.5B years old is pretty recent compared to the 14B years of the universe, so there's no ancient history of the moon.
I'd say if you studied the moon, anything that happened in it's early lifetime is ancient so the protomoon and first billion years into it's existence, maybe.
I guess it's similar to how people studying evolution class Humans as a recent event, but people who study humans class the the Pyramids as ancient history.
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[ 2.9 ms ] story [ 47.7 ms ] thread2 Billion years ago.
Not recent by any stretch of the imagination.
For example the margin either side of it being 2 billion is 59 million years either way...
I'd say if you studied the moon, anything that happened in it's early lifetime is ancient so the protomoon and first billion years into it's existence, maybe.
I guess it's similar to how people studying evolution class Humans as a recent event, but people who study humans class the the Pyramids as ancient history.