AGE OF THE MOON
1. Context
More than 50 years after astronauts returned with the last batch of Apollo-era moon rock, scientists have said they made a finding that would have been impossible in 1972.
2. How old is the moon?
- The recent study suggests that the moon's age is approximately 40 million years older than previously estimated.
- According to the updated findings, the moon is now believed to have originated around 4.46 billion years ago, or "4.46 GA," placing its formation within the initial 110 million years of our solar system's existence.
- Numerous lunar specimens have undergone examination throughout the years, although a considerable portion has been conserved and released to researchers at a gradual pace.
- This cautious approach was rooted in the early anticipation that advancing technology would eventually offer improved insights.
- The results, which were published on October 23, 2023, in Geochemical Perspectives Letters, are based on a novel technology known as atom probe tomography (APT)
3. Discovery of the moon's age
- The researchers conducted a fresh analysis of crystals taken from lunar sample 72255, which was previously identified to contain zircon crystals dating back 4.2 billion years, making them among the most ancient ever discovered.
- Zircon is recognized as the Earth's oldest known mineral and is of great importance to geologists as it offers crucial insights into the formation of our planet and the development of life as we understand it.
- In their recent study, the scientists employed Atom Probe Tomography (APT), a technology with incredibly fine spatial resolution, to assess the arrangement of lead within the samples.
- The distribution of lead is a commonly utilized factor in estimating the age of zircon crystals within rock formations.
3.1. Conventional method to find moon's age
- Discovering the moon's new age or refining its estimated age involves advanced scientific research and the analysis of lunar samples. Here's how this process typically works:
- Lunar samples, such as rocks and minerals, are collected from the moon's surface during missions like the Apollo program. These samples are brought back to Earth for analysis
- Scientists study these lunar samples in laboratories, often using a range of sophisticated instruments and techniques. Some of these techniques include radiometric dating and isotope analysis
- Radiometric dating methods, like uranium-lead dating or rubidium-strontium dating, are commonly used. These methods rely on the radioactive decay of certain isotopes within the lunar samples. By measuring the ratio of parent isotopes to daughter isotopes, scientists can estimate the age of the sample
- In addition to dating, scientists may perform isotope analysis on the samples. This involves examining the ratios of different isotopes of elements within the lunar material. Isotope ratios can provide information about the moon's history and its relationship with other celestial bodies
- New and advanced technologies, such as atom probe tomography (APT) or mass spectrometry, may be used to analyze lunar samples with higher precision. These technologies can provide more accurate data and help refine age estimates.
- Scientists compare the results obtained from lunar samples with other data, such as Earth's geological history and the age of the solar system, to better understand the moon's formation and evolution.
- The findings are typically published in scientific journals and subjected to peer review by the scientific community. This ensures that the research methods and conclusions are rigorously evaluated
- The age of the moon is then refined based on the new data and research findings. Any new information or breakthroughs in dating techniques can lead to adjustments in the moon's estimated age
4. Way forward
There were subsequent bombardments of the moon’s surface, which the researchers write “reworked and melted the earliest crust,” leaving some zircon modified and other zircon pristine, or preserved.
It was by spotting the preserved zircon within crystal grains from lunar sample 72255 that they were able to redetermine the moon’s age
The Earth is estimated to be between 4.5 and 4.6 billion years old. That makes the moon only a fraction younger, at 4.46 billion years old
Source: indianexpress
