- 4407 - MOON - how old is the moon? - Moon is 40 million years older than we thought, tiny crystals from Apollo mission confirm. A new analysis of zircon crystals from the Apollo 17 mission has revealed that the moon formed around 40 million years earlier than past geological evidence suggested. However, our cosmic companion may be even older than that.
------------------------- 4407 - MOON - how old is the moon?
- The moon is at least 40 million years older
than we once thought. Now we think it
is 4.42 million years old. Scientists confirmed our cosmic companion's
new minimum age after reanalyzing tiny impact crystals from lunar samples taken
by NASA's Apollo 17 mission in 1972.
-
- In a 2021 study, researchers first analyzed
the lunar gems, known as zircon crystals.
These are microscopic rocks created under intense heat and pressure
that, on Earth, are used to date objects such as impact craters. The lunar
grains were left behind when the moon formed following a colossal collision
between Earth and a Mars-size planet, named Thea.
-
- The analysis, which involved measuring the
decay rate of different versions, or isotopes, of uranium and lead in the
crystals' outer layers, revealed that the samples could be up to
4.46 billion years old.
-
- However, the 2021 study authors noted that there was a large amount of uncertainty in their dating method. As
a result, the oldest confirmed lunar zircon crystals remained a group that was part of a separate Apollo 17 sample that was analyzed in a 2009 study, which put the moon's earliest possible birth date at around 4.42 billion years ago.
-
- This new study, Oct. 23, 2023, reanalyzed
the crystals from the 2021 study, paying close attention to how the lead atoms
clustered within the crystals. This confirmed that the crystals are indeed
around 4.46 billion years old.
-
- These crystals are the oldest known solids
that formed after the giant impact.
And, because we know how old these crystals are, they serve as an anchor
for the lunar chronology.
-
- Earth is approximately 4.54 billion years
old. So based on the newest study, the zircon crystals were formed around 80
million years after our planet formed. However, the collision that birthed the
moon could have actually happened even earlier.
-
- After the Earth-Thea crash, the infant
moon's surface would have been covered by a magma ocean due to the intense
energy of the collision. Therefore, the lunar zircon crystals could only have
properly solidified into their current state once the magma ocean had cooled
down.
-
- In a 2017 study, researchers created a
computer model based on data from multiple lunar zircon samples to predict how
long the magma cooling process may have taken and, as a result, when the
collision actually took place. This revealed that the moon could be up to 4.51
billion years ago.
-
- Our understanding of the moon's history and
geological evolution is constantly changing with new discoveries.
-
- In July, 2021, researchers revealed that the "man in
the moon" is 200 million years older than previously thought. And in
November 2022, lunar samples collected by China's now-defunct Chang'e 5 rover
revealed that volcanic eruptions occurred on the moon as recently as 2 billion
years ago, which is around 1 billion years later than we realized.
-
- Therefore, there is every chance that the
moon's official birth date will be revised again at a later date. I have enough trouble remember my own
birthday.
-
-
March 23, 2023 MOON - how
old is the moon? 4401
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--------------------- --- Wednesday, March 27,
2024
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