In recent research, scientists discovered a significant disruption in the ionosphere of Earth. This major event was reportedly triggered by a gamma-ray burst (GRB) initiated by a supernova explosion in a galaxy located nearly two billion light-years from our planet.
The Supernova Event and its Gamma-Ray Surge
Approximately two billion years ago, a massive star met its climactic end in a colossal explosion known as a supernova in a distant galaxy beyond the Milky Way. This phenomenal occurrence released an enormous surge of gamma rays that journeyed across the cosmos before finally reaching Earth in 2022.
Studying the Effects with the China Seismo-Electromagnetic Satellite
The China Seismo-Electromagnetic Satellite (CSES), also known as Zhangheng, played a crucial role in studying these gamma rays’ effects. The satellite, part of a Chinese-Italian mission launched in 2018, contains the Electric Field Detector (EFD) instrument which provided unparalleled resolution for analysis.
Researchers observed an extraordinary disturbance in the Earth’s ionosphere caused by the GRB. The ionosphere extends 30-600 miles above the planet’s surface. This disturbance was detected in October 2022, and registered by the European Space Agency’s Integral (International Gamma-Ray Astrophysics Laboratory), along with several other satellites near Earth.
The Impact of Gamma Rays on the Ionosphere’s Electric Field
The electric field of Earth’s ionosphere underwent a significant variation due to the impact of the gamma rays. These rays lingered for about 13 minutes, affecting the ionosphere for several hours, even activating lightning detectors in India. These findings led to the identification of this GRB as the most potent ever recorded.
Gamma Ray Burst: The Brightest Electromagnetic Event in the Universe
Gamma-ray bursts are short-lived explosions of gamma rays, the most energetic form of light. These bursts can last from a few milliseconds to several hours and shine hundreds of times brighter than a regular supernova and about a million trillion times as bright as the sun. Astronomers classify GRBs into long- and short-duration events. While these two types of events likely result from different processes, both lead to the creation of a new black hole.
Ionosphere: Earth’s Shield from Solar Radiation
The ionosphere is a region of Earth’s upper atmosphere that spans an altitude of approximately 30 to 600 miles above the Earth’s surface. It is ionized by solar radiation, forming a layer of charged particles. The ionosphere is highly sensitive to changes in space’s magnetic and electrical conditions, usually linked to solar activity. It also expands and contracts in response to solar radiation.
The ionosphere plays a significant role in reflecting and refracting radio waves back to Earth, enabling long-distance communication via radio transmissions. It shields Earth from harmful solar radiation, specifically extreme ultraviolet rays from the sun. Furthermore, interactions between charged particles from the sun and Earth’s magnetic field in the ionosphere create luminous displays like auroras predominantly seen at high latitudes.
Exploring Gamma-Ray Bursts and Black Holes
In recent UPSC Civil Services Examination, a question related to this topic was asked. The question was, “Recently, scientists observed the merger of giant ‘blackholes’ billions of light-years away from the Earth. What is the significance of this observation?” The correct answer (b) stated that ‘Gravitational waves’ were detected in the process, further emphasizing the importance of understanding celestial phenomena.