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A spacecraft launched by US astronauts onto the Moon’s surface could trigger tiny tremors, called moonquakes, according to a new study.
Researchers revealed a previously unknown form of seismic activity on the Moon for the first time through analysis of Apollo-era data using modern algorithms.
The report suggests that large-scale temperature fluctuations on the Moon could cause expansion and contraction of man-made structures, causing these vibrations. According to a news release about the study, the moon’s surface is an extreme environment, fluctuating between minus 208 degrees Fahrenheit (minus 133 degrees Celsius) in darkness and 250 degrees Fahrenheit (121 degrees Celsius) in direct sun. .
In fact, the entire surface of the moon expands and contracts in cold and heat, according to the study published September 5 in the Journal of Geophysical Research: Planets. Yet scientists were able to use a form of artificial intelligence According to a summary of the study conducted by researchers at the institutes, to gain such an in-depth understanding of Apollo-era data they were able to emanate from the Apollo 17 lunar lander module, sitting just a few hundred yards from the instruments recording the Moon’s earthquakes. Can indicate light tremors. Which includes California Institute of Technology and NASA. (NASA provided funding for the study.)
This analysis provides new insights into how the Moon reacts to its surroundings and what may influence its seismic activity. The thunder was not dangerous and would probably be invisible to humans standing on the Moon’s surface.
Experts said understanding the moon’s tremors could be essential to future exploration, should NASA and its partners build a permanent outpost on the moon’s surface — a goal of the agency’s lunar exploration program Artemis.
“How much do we need to strengthen our structures, and what other threats do we need to mitigate?” Dr. Angela Marusiak, assistant research professor at the Lunar and Planetary Laboratory at the University of Arizona, said of those questions this type of data analysis could help answer. Marusiak was not directly involved in the study, although she had contact with the authors as a fellow expert in lunar seismology.
Marusiak said that every Apollo mission carried instruments to detect lunar earthquakes. But the Apollo 17 mission, launched in 1972, was notable because it left behind a series of seismometers capable of detecting thermal moonquakes – or shaking induced by extreme heating and cooling of the lunar surface.
“Thousands of these signals were recorded during an 8-month period from 1976 to 1977 on four seismometers deployed during the Apollo 17 Lunar Seismic Profiling Experiment, but the poor quality of the data makes analysis difficult,” the researchers wrote. ” “We have developed algorithms to accurately determine the arrival time of the waves, measure the strength of the seismic signal, and trace the direction of the lunar source.”
Scientists revisited the data for the first time in decades. The latest analysis helped the research team conclude that a certain type of lunar earthquake – called an impulsive thermal moon earthquake – did not come from natural sources, but rather from the heating and cooling of nearby spacecraft. .
“Every lunar morning when the sun hits the lander, it starts out,” Alan Husker, research professor of geophysics at Caltech and co-author of the study, said in a statement. “Over a period of five to seven Earth hours, every five to six minutes (there was) another event. They were incredibly routine and repetitive.
these shocks According to the study, this is different from another type of moonquake, called an incidental thermal moonquake, which is likely caused by the ground’s natural reaction to exposure to sunlight.
The researchers said they hope future lunar missions will offer an even more holistic picture of the phenomenon.
In addition to thermal earthquakes, deep and shallow tremors as well as activity caused by meteorite strikes have also been observed on the Moon.
It is important to note one important difference between the Moon and Earth: on the Moon’s surface, there are no shifting tectonic plates that could cause catastrophic events. But the Moon has an active internal life, and — like Earth — some type of seismic event can occur at any time or place on the lunar surface, Marusiak said.
Marusiak was curious about India’s lunar lander mission, Chandrayaan-3, which also included a seismometer. The Indian Space Research Organization has already confirmed that the instrument was capable of detecting moonquakes. (ISRO researchers have not yet released comprehensive data on the recording or proposed any suggested cause of the incident.)
The Chandrayaan-3 instrument, which first recorded activity near the moon’s south pole, was shut down in early September. Researchers will attempt to wake the spacecraft for further data collection on September 22, when sunlight will again enter the Chandrayaan landing site.
“I’m hoping that with the Artemis program, seismometers will continue to be included because they’re really important to understanding what’s happening not only at the surface, but also deeper in the regolith (soil),” Marusiak said.
But scientists are excited that studying Apollo-era data with modern technology could yield fascinating new results.
“It’s important to know as much as we can from existing data so we can design experiments and missions to answer the right questions,” Husker said. “The Moon is the only planetary body other than Earth that has more than one seismometer at any one time. “This gives us the only opportunity to study another body in depth.”