The study of soil has changed ideas about the age of the Earth's satellite
Scientists have found out how old the Earth's natural satellite actually is. They were able to analyze lunar dust collected by Apollo 17 astronauts in the 1970s. The study showed that the Moon is 40 million years older than previously thought.
During the manned space flight Apollo 17 About 243 pounds of lunar soil and rock samples were collected. On December 11, 1972, NASA astronauts Eugene Cernan and Harrison Schmitt collected rocks and dust from the surface of the moon. Today, these materials have allowed scientists to understand exactly when the Moon was formed, therefore, its exact age has become known, CNN reports. The results were published Monday, October 23, in the scientific journal Geochemical Perspectives Letters.
The new analysis finds that the zircon crystals can be dated back to 4.46 billion years ago. Previous estimates place the Moon at 4.425 billion years old. But according to a new study, it turns out that the Moon is 40 million years older.
“Since we know how old these crystals are, they serve as an anchor for the lunar chronology,— said cosmochemist and University of Chicago professor Philip Heck. – The main hypothesis for the formation of the Moon is that during the early history of the chaotic development of the solar system, an object the size of Mars, called Theia, crashed into the primordial Earth. This explosion threw magma into space, creating a disk of debris that orbited the Earth and later merged into the Moon. But the exact time of the satellite's formation has been difficult to determine; even the latest research may be wrong. This is because the crystals collected on the lunar surface by astronauts could have formed after the magma cooled and solidified. Before this, “their chemical fingerprint would have been erased.”
“The Moon is an important partner in our planetary system. It stabilizes the Earth's rotation axis, it's the reason there are 24 hours a day, it's the reason we have tides. Without the Moon, life on Earth would look different. It's part of our natural system that we want to better understand, and our research represents a tiny piece of the puzzle in the whole picture.» recalls the importance of the Moon and its study by Professor Heck.
The researchers used the atom probe tomography method. It is used to confirm the age of the oldest zircon crystals inside a fragment of rock called norite, formed after the Big Bang and collected by astronaut Schmitt. The research method uses ultraviolet lasers to evaporate atoms from the surface of the tip with particles of lunar soil. Atoms pass through a mass spectrometer, and how fast they move tells scientists how heavy they are and what they are made of.
Although lunar samples were collected in the 1970s, it took time to develop technology necessary for crystal analysis. That's why NASA has only in recent years begun to recover pieces from the Apollo era, which provide more information about our planet's moon using the most advanced research techniques.
“I like the fact that this study was done on a sample that was collected and brought to Earth 51 years ago. At that time, atomic tomography had not yet been developed, and scientists could not even imagine what types of analyzes we conduct today,” — Philipp Heck commented on the technological progress of our time.
The zircon-bearing rock was collected from the Taurus-Littrow Valley on the southeastern edge of the moon's Mare Tranquility and was stored at NASA's Johnson Space Center in Houston.
«Interestingly, all the oldest minerals discovered on Earth , Mars and the Moon, are zircon crystals. Zircon lasts forever,” — notes planetary scientist and study co-author Bidong Zhang.
Zhang's study, published in 2021, used a different method — ion microprobe analysis. It is used to measure the number of uranium and lead atoms in crystals and calculate the age of zircon based on the decay of radioactive uranium into lead over time. The ages that were claimed that year had to be confirmed by other methods due to potential complications associated with lead atoms if defects existed in the crystal structure of the zircon.
«I view this as an excellent example of what the nanoscale or even the atomic scale can tell us about global issues,” — noted lead study author Jennika Greer.
The Moon, which orbits the Earth at an average distance of about 384 thousand kilometers, has a diameter of about 3.5 thousand kilometers, which is slightly more than a quarter of the diameter of our planet.
< p>«The moon helps stabilize the earth's axis for a stable climate. The Moon's gravitational pull helps shape the ocean ecosystem. The Moon inspires human cultures and exploration. And NASA and other space agencies see the Moon as a stepping stone for future deep space exploration,” — Zhang adds.