12 Space Telescope Discoveries That Reshaped Our Understanding of the Universe

7. Gamma-Ray Bursts - The Universe's Most Powerful Explosions

Space-based gamma-ray telescopes have revealed gamma-ray bursts (GRBs) as the most energetic explosions in the universe since the Big Bang, fundamentally changing our understanding of stellar death and cosmic violence. These brief but incredibly intense flashes of gamma radiation were first detected by military satellites in the 1960s, but it wasn't until dedicated space telescopes like the Compton Gamma Ray Observatory and later the Swift and Fermi missions that astronomers began to understand their true nature. GRBs are now known to occur when the most massive stars collapse into black holes or when neutron stars merge, releasing in seconds more energy than the Sun will produce in its entire 10-billion-year lifetime. The discovery that GRBs occur in distant galaxies revealed that these explosions can be seen across most of the observable universe, making them valuable tools for studying the early cosmos and the formation of the first generation of stars. Space telescopes have identified two distinct classes of GRBs: short bursts lasting less than two seconds, typically associated with neutron star mergers, and long bursts that can last several minutes, linked to the collapse of massive stars called hypernovae. The study of GRBs has also revealed their potential role in shaping galactic evolution, as these powerful explosions can sterilize large regions of space and may have influenced the development of life in the early universe by stripping away protective atmospheres from planets within their reach.