The moon may have formed at least 4.46 billion years ago. This is 40 million years earlier than we thought.
NASA/JPL/USGS
Lunar Luke’s reanalysis has delayed the moon’s age by 40 million years. This means it was formed at least 4.46 billion years ago.
Scientists believe the moon formed after a planet the size of Mars collided with Earth, sending a ball of molten rock into space. When the magma surface of this object cooled and solidified, silicon crystals called zircon formed. Due to its resistance to heat and harsh environments, this crystal still survives and can be used to identify the earliest moments of the moon.
Zircon crystals contain radioactive uranium, which decays to lead at a well-defined rate, allowing scientists to determine the age of rock samples by measuring the amounts of lead and uranium in them. Masu.
philip heck and his colleagues at the University of Chicago used a technique called atom probe tomography to reanalyze zircon samples taken from moon rocks brought back from NASA’s Apollo 17 mission in 1972. discovered that it is 4.46 billion years old.
“Now that we know the age of the zircons, we can tell when the magma ocean solidified or largely solidified,” Heck said. “It’s essentially anchoring the entire lunar chronicle. It’s like driving a nail. On the monthly timeline. ”
The particular zircon sample that Heck and his team examined was Analyzed in 2021 Using some type of mass spectrometry, it suggested that the sample was old, but the technique cannot pinpoint whether the lead was due to radioactive decay or was there by chance. did.
However, atom probe tomography allows detailed analysis of the composition and position of atoms, which can show that the atoms are actually due to radioactive decay. A beam of charged particles is used to scrape extremely thin sections of just a few atoms from the sample, and a powerful laser vaporizes these atoms into a mass spectrometer.
We know that the solar system was formed about 4.57 billion years ago. This means we can constrain the moon’s formation quite precisely.” Mahesh Anand At the Open University, UK.
“Previous studies have shown that the particular impact that formed the Moon occurred 50 million years after the formation of the solar system, and using that study and this study, we have a very narrow window of only 50 million years. You are given a time frame, within which the moon formed and solidified very quickly,” says Anand.
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