The Earth's poles rotated 41,000 years ago in an unusual event that caused the magnetic field to weaken, allowing cosmic rays to hit the atmosphere.
And now we humans have heard for the first time the terrifying sounds of the so-called Laschamp event.
Scientists used satellites to map lightning strikes on our planet, capturing what sounded like breaking wood and crumbling rocks.
The magnetic field protects our planet from solar wind and if the Laschamp event were to occur today, it could wreak havoc on the electrical network and leave life on the surface exposed to greater amounts of solar radiation.
And the haunting soundscape captured in the new video occurred when the region was only five percent of its current strength.
Scientists mapped Earth's magnetic field using a swarm of satellites. That allowed them to recreate the sounds of the region when it rotated 42,000 years ago.
The soundscape was captured using data from a constellation of European Space Agency satellites.
The researchers mapped the movement of Earth's magnetic field lines during the event and produced a stereo sound version using natural noises.
Scientists have been monitoring Earth's magnetic field for decades, waiting for the moment when it spins again, a change in which the magnetic south pole would become the magnetic north, and vice versa.
Data has estimated that Earth's north and south magnetic poles change every 200,000 to 300,000 years.
A study conducted in 2018 revealed that it has been approximately 780,000 years since the last such event, leading many to suspect that it was about time.
Professor Roberts of the Australian National University said at the time: “Earth's magnetic field, which has existed for at least 3.45 billion years, provides a shield against the direct impact of photovoltaic radiation.
“Even with Earth's current strong magnetic field, we are still susceptible to solar storms that can damage our electricity-based society.”
The research analyzed the paleomagnetic record from 107,000 to 91,000 years ago by analyzing a stalagmite from a cave in southwest China.
The team performed magnetic analysis and radiometric dating on the meter-long sample, revealing the behavior of the ancient magnetic field.
And they found that the magnetic field underwent a rapid change over the span of about two centuries, decreasing in strength by about 90 percent when a field reversal occurred.
A more recent study from 2021 attributed the extinction of the Neanderthals to the reversal of the Earth's magnetic field.
Australian researchers analyzed the radiocarbon record of ancient trees in New Zealand that were alive when the magnetic poles flipped.
The trees revealed spikes in atmospheric radiocarbon levels, caused by the collapse of Earth's magnetic field and changing solar winds.
Researchers called this period of danger the “Adams Transition Geomagnetic Event,” or “Adams Event” for short, a tribute to science fiction writer Douglas Adams.
The spin weakened the magnetic field, allowing cosmic rays to hit Earth's atmosphere.
The British author wrote in The Hitchhiker's Guide to the Galaxy that '42' was the answer to life, the universe and everything.
Chris Turney, co-author of the study, said: “For the first time, we have been able to precisely date the timing and environmental impacts of the last magnetic pole shift.
'The finds were made possible by ancient New Zealand kauri trees, which have been preserved in sediments for more than 40,000 years.
“Using the ancient trees we were able to measure and date the increase in atmospheric radiocarbon levels caused by the collapse of the Earth's magnetic field.”
The team found that Earth's magnetic field weakened by only up to six percent, leaving “essentially no magnetic field at all.”
During the breakdown of the magnetic field, the Sun experienced several grand solar minima (GSMs): prolonged periods of quiet solar activity.
Although a GSM means less activity on the Sun's surface, the weakening of its magnetic field may mean that more space weather (such as solar flares and galactic cosmic rays) could be headed toward Earth.
“Unfiltered radiation from space tore apart air particles in Earth's atmosphere, separating electrons and emitting light, a process called ionization,” Professor Turney said.
“The ionized air fried the ozone layer, causing a shock wave of climate change around the world.”
The Adams Event could explain many other evolutionary mysteries, such as the extinction of the Neanderthals and the sudden widespread appearance of figurative art in caves around the world.
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