A huge burst of gamma rays has been detected. ESA’s Integral Space Telescope, crashed into Earth. This explosion caused significant disruption to the ionosphere of our planet. Such disturbances are usually associated with high-energy particle events on the Sun, but this one was the result of an exploding star nearly 2 billion light-years away. Analyzing the effects of explosions could provide information about mass extinctions in Earth’s history.
Detection of the brightest gamma-ray bursts
On 9 October 2022 at 14:21 BST / 15:21 CEST, an extremely bright and long-lasting gamma-ray burst (GRB) struck many high-energy satellites in near-Earth orbit, including ESA’s Integral. detected by. Mission.
The International Gamma-ray Astrophysics Laboratory (Integral) was established by ESA in 2002 and has been detecting gamma-ray bursts almost every day since then. But GRB 221009A, as the name of the explosion suggests, was anything but ordinary. “This was probably the brightest gamma-ray burst ever detected,” says Mirco Piersanti, from the University of L’Aquila in Italy and lead author of the team that published these results.
Understanding gamma ray bursts
Gamma-ray bursts were once a mysterious event, but they are now recognized to be bursts of energy from the explosion of a star called a supernova, or the collision of two ultra-dense neutron stars.
“We have been measuring gamma-ray bursts since the 1960s, and this is the most powerful one ever measured,” said co-author and author of the National Institute of Astrophysics in Rome, Italy. said Pietro Ubertini, principal investigator of Intergral’s IBIS instrument. In fact, its closest rival on record is 10 times weaker. Statistically, a GRB as powerful as GRB 221009A will reach Earth only once in 10,000 years.
Impact on the Earth’s ionosphere
During the 800 seconds that the gamma rays hit, the burst provided enough energy to set off India’s lightning detectors. German instruments picked up signs that the Earth’s ionosphere was disturbed by the explosion for several hours. This extreme amount of energy gave the team the idea to study the impact of the burst on the Earth’s ionosphere.
The ionosphere is a layer of Earth’s upper atmosphere that contains electrically charged gases called ionospheres. plasma. The altitude ranges from approximately 50km to 950km. Researchers call this the upper ionosphere above 350 km and the lower ionosphere below. The ionosphere is so tenuous that a spacecraft can maintain its orbit through a large portion of the ionosphere.
First observation of top-surface ionospheric disturbance
One of those spacecraft is the China Earthquake and Electromagnetic Satellite (CSES) (also known as Zhangheng), a Sino-Italian space mission. Launched in 2018, it will monitor changes in the electromagnetic behavior of the upper surface of the ionosphere. Its main mission is to study possible links between changes in the ionosphere and the occurrence of seismic phenomena such as earthquakes, but it can also study the effects of solar activity on the ionosphere.
Mirko and Pietro were both part of CSES’s scientific team and knew that if GRB caused a disruption, CSES should be aware of it. But they weren’t sure. “We have looked for this effect in other his GRBs in the past and found nothing,” says Pietro.
In the past, GRBs have been found to affect the lower ionosphere at night when the effects of sunlight are removed, but never in the upper side. Therefore, by the time the explosion from the GRB reached Earth, it was thought that it would no longer be powerful enough to cause changes in the conductivity of the ionosphere that would lead to electric field fluctuations.
But this time, when scientists looked into it, their luck was different. The effect was clear and powerful. For the first time ever, they observed severe perturbations in the upper ionosphere in the form of strong electric field fluctuations. “It’s amazing. It shows us not only what’s happening in deep space, but it’s also having an impact on Earth,” says ESA project scientist Eric Kulkers.
Widespread effects of gamma-ray bursts
This particular GRB originated in a galaxy nearly 2 billion light-years away. So 2 billion years ago, it still had enough energy to affect Earth. The Sun is normally the main source of radiation powerful enough to affect Earth’s ionosphere, but this GRB is set aside to study giant explosions in the Sun’s atmosphere, commonly known as solar flares. Triggered the device. “Remarkably, this disturbance affected the lowest layers of Earth’s ionosphere, located just tens of kilometers above the Earth’s surface, leaving a footprint comparable to a large solar flare,” ESA said. says Laura Hayes, a solar physicist and researcher at .
Impact on the Earth
This signature appeared in the form of increased ionization in the bottom ionosphere. It was detected from very low frequency radio signals bouncing between the ground and the Earth’s lower ionosphere. “Essentially, we can say that the ionosphere has ‘moved’ to a lower altitude, and we detected this by the way radio waves bounced along the ionosphere,” Laura explains. We have published these results In 2022.
This strengthens the idea that a supernova in our galaxy could have even more serious consequences. “There has been great debate about the possible effects of gamma-ray bursts in our galaxy,” says Mirko.
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 the earth’s surface. It has been speculated that such effects may be responsible for several mass extinctions known to have occurred on Earth in the past. However, more data will be needed to investigate this idea.
Now that they know exactly what to look for, the team has already started looking back at the data collected by CSES and correlating it with other gamma-ray bursts observed by Integral. And although it only dates back to 2018, when CSES was launched, follow-up missions are already being planned and will continue to open up this fascinating new window into the way Earth interacts with the very distant universe. We guarantee that you will
Reference: “Evidence for perturbations in the upper ionospheric electric field correlated with gamma-ray bursts” Mirko Piersanti, Pietro Ubertini, Roberto Battiston, Angela Bazzano, Giulia D’Angelo, James G. Rodi, Piero Diego, Zhima Zeren, Roberto Ammendola, Davide Ammendola Badoni, Simona Bartocci, Stefania Beore, Igor Bertello, William J. Berger, Donatella Campana, Antonio Ciccone, Piero Cipollone, Silvia Colli, Livio Conti, Andrea Contin, Marco Cristoforetti, Fabrizio De Angelis, Cinzia De Donato, Cristian De Santis, Andrea Di Luca, Emiliano Fiorenza, Francesco Maria Forega, Giuseppe Gebbia, Roberto Juppa, Alessandro Rega, Marco Roli , Bruno Martino, Matteo Martucci, Giuseppe Massiantonio, Matteo Merge, Marco Mese, Alfredo Morbidini, Coralie Neubuser, Francesco Nozzoli, Fabrizio Nuccilli, Alberto Oliva, Giuseppe Osteria, Francesco Palma , Federico Palmonari, Beatriz Panico, Emanuele Papini, Alexandra Palmantier, Stefania Persivali, Francesco Perfetto, Alessio Perrinelli, Piergiorgio Picozza, Michele Pozzato, Gianmaria Revastini, Dario Recchiuti, Esther Ricci, Marco Ricci, Sergio B. Ricciarini, Andrea Russi, Zuleika Sarnoun, Umberto Savino, Valentina Scotti, Xuhui Shen, Alessandro Sottogiu, Roberta Sporvoli, Silvia Tofani, Nero Veltoli, Veronica Villona, Vincenzo Vitale, Ugo Zannoni, Simona Zoffoli, Paolo Zuccon, November 14, 2023, nature communications.
DOI: 10.1038/s41467-023-42551-5