Gamma-ray burst from distant exploding star hits Earth
An enormous burst of gamma rays, originating from an exploding star almost two billion light-years away, has struck Earth, causing a significant disturbance in our planet’s ionosphere. This event, named GRB 221009A, is the brightest and strongest gamma-ray burst ever detected. The burst delivered enough energy to activate lightning detectors in India and caused a disturbance in Earth’s ionosphere for several hours.
Gamma-ray bursts were once mysterious events but are now known to be the outpouring of energy from exploding stars or the collision of super-dense neutron stars. This particular burst is so powerful that it arrives at Earth only once every 10,000 years statistically. The burst’s effects on Earth’s ionosphere were studied by the China Seismo-Electromagnetic Satellite (CSES), which monitors the top side of the ionosphere for changes in its electromagnetic behavior. The CSES science team observed an intense perturbation in the form of a strong electric field variation in the top-side ionosphere, a phenomenon never seen before.
In the past, gamma-ray bursts have been observed affecting the bottom-side ionosphere during the night when solar influence is minimal. It was believed that by the time a burst reached Earth, it was no longer powerful enough to produce a variation in the ionospheric conductivity. However, this recent burst has proven otherwise. Despite taking place in a galaxy almost two billion light-years away, it still had enough energy to affect Earth’s ionosphere.
The impact of the burst on Earth’s ionosphere was comparable to that of a major solar flare. It caused an increase in ionization in the bottom-side ionosphere, which was detected through radio signals that bounce between the ground and Earth’s lower ionosphere. This new finding raises concerns about the consequences of a gamma-ray burst in our own galaxy. In the worst-case scenario, a burst could not only affect the ionosphere but also damage the ozone layer, allowing dangerous ultraviolet radiation from the Sun to reach Earth’s surface. This effect has been speculated to be a possible cause of mass extinction events in Earth’s history.
To further investigate this concept, more data is needed. The scientists behind the study are now correlating the data collected by CSES with other gamma-ray bursts observed by ESA’s Integral mission. While they can only go back to 2018 when CSES was launched, a follow-up mission has already been planned to continue studying the interaction between Earth and the distant Universe.
This groundbreaking research provides a fascinating new window into how Earth interacts with the universe and highlights the potential consequences of gamma-ray bursts on our planet. It also emphasizes the need for continued scientific exploration and data collection to better understand these cosmic events and their impact on Earth’s environment.
