The moon seems to be roughly 40 million years older than beforehand thought, new analysis reveals. (This story first aired on All Issues Thought of on October 27, 2023.)
SCOTT SIMON, HOST:
In December 1972, astronauts on the Apollo 17 mission went rock searching on the moon.
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EUGENE CERNAN: Earlier than we cowl them up, let’s get them. I obtained to get a pattern of that mom rock.
SIMON: They led to 250 kilos of moon rock again to Earth. These samples are nonetheless being studied as we speak. NPR’s Regina Barber experiences that scientists have now decided the moon is about 40 million years older than beforehand thought.
REGINA BARBER, BYLINE: The moon is roughly 4.5 billion years previous. So what does an additional 40 million years imply on this time scale? Jenniker Greer is the lead writer of the research, printed in Geochemical Perspective Letters. This is how she sees it.
JENNIKER GREER: That 40 million years is important once you have a look at the very dynamic early historical past of those two objects. Lots of stuff occurred within the early photo voltaic system in a short time.
BARBER: Within the early days of our photo voltaic system, an object the scale of Mars smashed instantly right into a forming Earth.
GREER: After which they smushed collectively, and materials kind of peeled off to type the moon.
BARBER: A sizzling moon that had a magma ocean. These Apollo 17 rock samples are crystals from that cooled ocean. To determine how previous these crystals are, scientists used radiometric relationship. As a result of uranium decays into a selected sort of lead over time, scientists can use it to work backwards and get an age. The issue is, if a few of that lead is misplaced over time or clumps collectively, it may throw off the age estimate. However new know-how can assist. For instance, Greer was ready to take a look at the pattern on the atomic degree to see if the lead was undisturbed.
GREER: The kind of measurements that we do on this work wouldn’t have been potential 50 years in the past. They would not have been potential 20 years in the past.
BARBER: This new age is no surprise to Marissa Tremblay, a geochronologist who did not work on this research however was impressed by the method.
MARISSA TREMBLAY: And so they’re actually tough measurements to make, too. So it’s totally thrilling to see these new outcomes.
BARBER: Although this older date is no surprise, Tremblay and Greer each agree it clarifies an vital piece of the puzzle for a way we, our planet, our moon got here to be what they’re as we speak.
TREMBLAY: When did that magma ocean begin to crystallize? It is telling us about that very early historical past of the moon. It is also telling us about when that massive impression occurred on the Earth.
BARBER: Tremblay additionally says that after relationship extra lunar samples, she would not be shocked if the age of the moon will get even older. Regina Barber, NPR Information.
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