Discovery of the Largest Solar Flare Ever
Researchers found unexpectedly high levels of carbon-14 in millennium-old tree trunks, which in turn led them to the discovery of the largest solar flare ever.
The sun is an unpredictable star, known for its bouts of intense activity, whereby it flings energy-rich particles towards our planet. Earth is luckily fitted with a sizable magnetic bubble to shield against such harmful solar outbursts. However, our radiocommunication systems and electrical grids tend to be more susceptible to solar activity. A recent study has revealed that the most massive solar explosion known to man occurred approximately 14,300 years ago, a time when such technologies were inexistent.
Analyzing Tree Trunks
The researchers focused on analyzing ancient tree trunks discovered in the French Alps. They sliced these into separate thinner pieces, and a thorough inspection led to a surprising revelation. It was found that there had been a significant increase in carbon-14 levels exactly 14,300 years ago. By comparing this carbon-14 spike to traces of beryllium, a chemical element found in Greenland ice cores, the research team concluded that this surge had been caused by a massive solar flare. This flare had injected enormous quantities of energy-rich particles into the Earth’s atmosphere.
The Role of Carbon-14
“Carbon-14 is continuously produced in the upper layers of the atmosphere due to reactions triggered by cosmic radiation,” explains research leader Edouard Bard. “It has been recently established that intense solar activity, like solar flares and coronal mass ejections, can also trigger brief bursts of energy-filled particles. These are stored as large peaks in the production of radiocarbon for only about a year.”
The Largest Solar Flare in History
The newly discovered solar flare, which took place around 14,300 years ago, was no ordinary event. Among the nine similar known solar explosions, referred to as ‘Miyake’ events, this was the largest. These events have all transpired over the last 15,000 years. The most recent Miyake events happened in 993 AD and 774 AD. However, the solar eruption that occurred approximately 14,300 years ago was twice as large as either of the two recent events. As a result, this major flare has now been recorded as the largest ever.
The scientists underscore that a similar solar eruption in today’s world could prove catastrophic for our technology-driven society, potentially bringing about the failure of communication systems, satellites, and power grids and causing significant financial damage.
Communication and Satellite Systems
“Intense solar flares can have enormous consequences for our planet,” says researcher Tim Heaton. “These superstorms can cause permanent damage to our power networks, leading to long-lasting power outages that can last for months. They can also harm the satellites that we use for navigation and communication, rendering them ineffective. Additionally, they pose substantial radiation risks for astronauts in space.”
Miyake Events
Despite this, we still know very little about the specific characteristics of catastrophic Miyake events because we have never been able to directly observe them. This highlights the fact that there is still much to learn about the sun’s behavior and the potential dangers it poses to our society. We do not yet fully understand what triggers these extreme solar flares, how often they can occur, or if there might be a way to predict them in the future.
Direct Measurements
The new study represents a significant step forward, offering fresh insights into the sun’s extreme behavior and associated risks for our planet. “We only started taking direct instrumental measures of solar activities in the 17th century, and back then, we were simply counting sunspots,” shares Bard. “Nowadays, we use Earth-based observatories, space explorers, and satellites to gather detailed data about the sun. But even with all our modern tools, our knowledge about the sun’s long history remains limited. Measuring carbon-14 in tree rings and analyzing beryllium in polar ice cores provides the best method to understand the sun’s behavior further back in time.”
Scientists emphasize the critical importance of understanding the future risks of large-scale solar flares better. They contend that understanding our past is vital for accurately forecasting our future and minimizing potential risks. “Measuring carbon-14 is a tremendously powerful method for investigating the Earth’s history and reconstructing major events,” says Heaton. The researchers hope that this knowledge will improve our preparedness, strengthen our communication and energy systems, and enhance their defense against potential damage.
