Weird But True: Kilonova Poses a Threat to Earth
By Brooke Kato
Published Nov. 2, 2023, 2:35 p.m. ET
Move over supernovas, there’s a new threat in town called kilonova. Scientists have discovered that these violent star collisions have the potential to devastate our planet by unleashing a deadly spew of radiation, including gamma rays, cosmic rays, and x-rays.
According to Haille Perkins, a researcher from the University of Illinois Urbana-Champaign, if a neutron star merger occurred within about 36 light-years of Earth, the resulting radiation could cause an extinction-level event. The collision of ultra-dense neutron stars, each weighing approximately one billion tons, creates a particle blast that not only destroys our planet’s ozone layer but also exposes it to harmful ultraviolet radiation for the next 1,000 years. The exact safety distance and the most dangerous component are uncertain since various factors such as viewing angle, blast energy, and ejected material mass come into play, reassures Perkins.
Out of all the lethal particles studied, cosmic rays pose the most viable concern. The collision would generate an expanding bubble of cosmic rays that would engulf everything in its path, bombarding Earth with highly energetic charged particles. Gamma rays are equally terrifying. They emit as two narrow jets from the merger, potentially obliterating any celestial object within a direct path of approximately 297 light-years. Even an indirect exposure to gamma radiation could significantly damage our ozone layer, taking about four years to repair. Moreover, when gamma rays collide with surrounding star dust, they produce X-ray emissions that have the same ionizing effect on the ozone layer. Although X-ray effects last longer than those of gamma rays, Earth would need to be approximately 16 light-years away to experience them, according to Perkins’ team.
Perkins’ team conducted a study on a neutron star merger that occurred in 2017, about 130 million light-years away. The collision resulted in a violent release of particles equivalent to 1,300 times the mass of Earth, offering insights into the creation of heavy elements like platinum, uranium, and gold. However, if Earth were to fall within the path of destruction, the effects of the kilonova would be catastrophic.
Despite these findings, Perkins emphasizes that kilonovas are rare, and there are other events such as solar flares, asteroid impacts, and supernova explosions that pose a greater potential threat. In a recent study, scientists observed the aftermath of a suspected kilonova using the James Webb Space Telescope for the first time. Andrew Levan, the lead author, explained that this breakthrough provides valuable information for future research.
While the threat of a kilonova is not imminent, it is important to continue studying and monitoring celestial events to ensure the safety of our planet. Stay curious, stay informed, and stay prepared.
