Electromagnetic Radiation and Cosmic Rays From Kilonova Could Endanger Life on Earth

(Photo: Wikimedia Commons/University of Warwick/Mark Garlick)
Electromagnetic Radiation and Cosmic Rays From Kilonova Could Endanger Life on Earth

Earth is not safe if it is too close to two neutron stars colliding. If this cosmic event happens, life on the planet could be endangered.

Earth Being Too Close To a Kilonova Is Not Safe

Scientists have predicted that a planet like Earth might face disastrous consequences if it is near two colliding neutron stars. A kilonova is a cosmic event that produces enormous amounts of energy in cosmic rays and electromagnetic radiation.

A recent study suggests that life on Earth might be wiped out if Earth were directly following one of these powerful radiation beams. Life would only be in danger if we were close to a kilonova. The safe distance would depend on the kind of radiation that struck us.

"Binary neutron star mergers produce high-energy emissions from several physically different sources, including a gamma-ray burst (GRB) and its afterglow, a kilonova (KN), and, at late times, a remnant many parsecs in size. Ionizing radiation from these sources can be dangerous for life on Earth-like planets when located too close," the authors wrote.

All three of these radiation types are hazardous; cosmic rays have the potential to evaporate the atmosphere and cause mass extinctions, while gamma and X-rays can ionize our atmosphere and expose us to solar winds and UV light from the sun.

If it were close enough, a hemisphere-wide EM [electromagnetic] pulse would result from the short [gamma-ray] cocoon emission ionizing the atmosphere. Furthermore, without any shield from the atmosphere, astronauts on the ISS or the Moon would be exposed to radiation from cosmic rays and gamma rays.

As the Apollo astronauts did, astronauts would see flashes of light even when their eyes were closed due to cosmic radiation. It would be difficult for people on Earth to avoid the muons created in the atmosphere, and they have been discovered to cause congenital disabilities and mutations.

What Is a Kilonova?

Kilonova is a powerful flare of electromagnetic radiation produced by the merger of two neutron stars or one neutron star and a stellar-mass black hole. Kilonovas are massive explosions greater than supernovas, and they are produced when a black hole and a neutron star collide.

In addition to releasing high-energy gamma rays, which are hazardous in and of themselves, they may crash with cosmic gas and dust and heat it, creating a potent X-ray afterglow. Being a transitory astronomical phenomenon, it manifests as a fleeting burst of light in the sky that eventually fades to nothing.

Life on Earth may likewise be in danger from these X-rays. Kilonovas release shockwaves called remnants, which have the potential to cause gas and dust along the shockwave's firing line to release cosmic rays.

The ultradense cores of dying massive stars, known as neutron stars, release significant material when these collisions occur. The periodic table's heaviest elements are formed in the furious sea of particles surrounding a neutron star merger, which is rich in neutral particles known as neutrons. These consist of radioactive elements like uranium, precious metals like gold and platinum, and the iodine in human blood. In actuality, a kilonova-triggering event is responsible for creating numerous jewelry items.