Context
Over half a century after astronauts returned with the final collection of moon rocks from the Apollo period, researchers found in their new study that the moon was formed about 4.46 billion years ago based on a new technology called Atom Probe Tomography (APT).
How did scientists discover the moon’s new age?
- The scientists re-examined crystals from lunar sample 72255, which was known to contain 2 billion-year-old zircon.
- Since zircon is the earliest mineral known to exist on Earth, it provides important insights into the genesis of life on Earth and the planet.
- Using APT, which has nanoscale spatial resolution, the researchers in the present study were able to identify the lead clustering in the samples.
- The distribution of lead is commonly used to estimate the age of zircon in rock.
Why is zircon relevant to the age of the moon?
- According to the researchers' analysis, the leading hypothesis for the formation of the Earth-moon system is the giant impact hypothesis.
- In this hypothesis, Earth is believed to have crashed with a massive object known as Theia, which may have been as large as Mars.
- Researchers say that caused an ejection of debris that quickly formed into the sphere we call our moon.
- There were subsequent bombardments of the moon’s surface, which left some zircon modified and other zircon pristine, or preserved.
- Researchers redetermined the moon’s age using the preserved zircon with crystal grains from lunar sample 72255.
