According to news on November 15, a new study shows that a supernova explosion in 2022 destroyed part of the ozone in the Earth’s atmosphere in a short period of time, temporarily affecting the natural barrier that protects people from harmful solar radiation. The related paper was published in the journal Nature Communications on Tuesday local time.
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On October 9, 2022, the space telescope captured a stream of high-energy photons flying towards the Earth.Confirmed a supernova explosion 1.9 billion light years away from Earththis event is called a gamma-ray burst, and researchers call it the “brightest” supernova explosion ever.
A team of scientists found that the supernova explosion caused measurable changes in the number of ionized particles in Earth’s upper atmosphere, including ozone molecules that absorb harmful solar radiation.
“The ozone was partially depleted, temporarily destroyed,” said astronomer Pietro Ubertini of the National Institute of Astrophysics in Rome, who helped discover the atmospheric event.The effect only lasted a few minutes before the ozone repaired itself, so there were no “serious” consequences.. But if this supernova explosion happened much closer to us, “it would be a disaster.”
This study shows how explosive events even far away from the solar system can affect the atmosphere, which can also be regarded as a giant probe for extreme cosmic phenomena.
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Most ozone is concentrated in the thin layer of the stratosphere, about 16 to 40 kilometers above the surface. It was in this region that researchers discovered the ozone hole above the Antarctic, caused primarily by chlorofluorocarbon chemicals that were once found in aerosol sprays and plastic foam. The ozone layer absorbs most of the sun’s ultraviolet radiation, preventing sunburn, skin cancer and crop damage.
Simulations show that if a gamma-ray burst occurred in our galaxy, the stratospheric ozone layer could disappear for years, enough to trigger widespread species extinction.
Ozone is also present in the ionosphere, but at lower concentrations. The ionosphere is a part of the atmosphere that extends from 60 kilometers to 500 kilometers above sea level. At this altitude, ozone has a certain protective effect, but it is far less effective than in the stratosphere.
To study the impact of last year’s gamma-ray burst on Earth,Dr. Ubertini and his colleagues used China’s Zhangheng-1 electromagnetic monitoring test satellite (China Seismo-Electromagnetic Satellite) data, looking for signals at the top of the ionosphere. Zhangheng-1, an orbiter used to study atmospheric changes during earthquakes, launched in 2018 from the Jiuquan Satellite Launch Center in China.
The researchers found a sharp rise in the electric field at the top of the ionosphere, a result they linked to gamma-ray burst signals measured by the European Space Agency’s International Gamma-ray Astrophysics Laboratory.
The researchers found that gamma rays ionize (knock electrons away from) ozone and nitrogen molecules high in the atmosphere, causing the electric field to increase 60 times in strength. Once ionization occurs, ozone molecules are unable to absorb ultraviolet radiation, briefly exposing Earth to more harmful solar rays.
Gamma-ray bursts are known to ionize ozone molecules at the base of the ionosphere 215 miles (346 kilometers) above the Earth’s surface. But this is the first time scientists have shown that such a cosmic explosion affects the entire ionosphere, said Laura Hayes, a solar physicist at the European Space Agency.
Dr. Hayes added that it is unusual for cosmic phenomena far from Earth to cause such large-scale atmospheric disturbances. She wrote in an email: “Fortunately, this gamma-ray burst occurred very far away, making its impact more of a scientific curiosity than a threat.. “
Dr. Ubertini said a gamma-ray burst a million times larger could ionize enough ozone to weaken the protective barrier for days or months. However, the likelihood of this happening is low. Supernova explosions as powerful as last year’s are extremely rare, occurring only once every 10,000 years. In addition, gamma rays are released from supernovae in the form of jets and need to be directed in the right direction to hit the Earth.
However, understanding the ionosphere’s response to any cosmic phenomenon is important for threats closer to Earth. Dr Hayes said: “This helps us assess recovery times after violent ionization, particularly in situations involving strong solar flares.”
The good news is that ozone repairs itself and the free electrons are eventually recaptured by ionized molecules in the air. In this case, part of the shield that protects Earth from space radiation could be restored, shielding Earth’s inhabitants from the sun’s deadly radiation.