The collision of two tightly packed neutron stars in a decaying orbit appears to be a relatively rare event. In the entire Milky Way galaxy, out of all 100 billion stars, scientists estimate that there are only about 10 binary neutron stars destined to collide. To date, we have only detected a few Kilonova explosions following such a collision, and none have been detected in our galaxy. What if there was a kilonova in the Milky Way? What does this mean for life on Earth?

According to a team led by physicist Hale Perkins of the University of Illinois at Urbana-Champaign, there is no benefit to having an explosion occur in a particular area. This information probably won’t be useful if two neutron stars collide really nearby, but it’s nice to know how deadly space can be.

The team’s findings, uploaded to the arXiv preprint server, show that the biggest danger is cosmic rays unless we are in the path of the Kilonova gamma-ray burst, 35 light-years away. If we’re on this path, we’ll get within lethal proximity of 300 light years, but we need to be in exactly the right place.

This will help us assess threats to our own existence and allow scientists to determine the likelihood of life surviving on alien worlds near these star-shattering events that explode with powerful, atmosphere-shattering radiation. Colliding neutron star binaries (based on the small number we observe) have several components.

What is usually seen is a short gamma-ray burst (supernovae that collapse single stars, the longer ones) that explode in a pair of narrow jets on either side of the colliding stars. The jet is trying to break up the falling material during the turning point.

When the jets hit the surrounding interstellar medium, they create powerful X-rays; This is known as X-ray afterglow. And as the situation evolves over years and centuries, a bubble of cosmic rays expands from the collision center into space. Based on what we know from the first neutron star collision, GW170817, Perkins and his team investigated how these events might affect the planet.

They found that any creature in the jet’s narrow range, 91 parsecs (297 light-years) away, was likely to be fried by the powerful gamma rays. However, it is a little safer outside this narrow range. You would need to be about 13 light years away to be exposed to gamma radiation from the cocoon structures.

Both of these threats will only be present for a short time; They will destroy Earth’s stratospheric ozone, and it will take about four years to repair. The team found that X-rays are much more lethal because the afterglow lasts much longer than gamma rays. But you still need to be relatively close; in about 16 light years.

Researchers found that the biggest threat is the long-term cosmic ray bubble. Accelerated by the Kilonova remnant, they will destroy the ozone, leaving the Earth defenseless and exposed to radiation for thousands of years. This would lead to a devastating mass extinction. For this we need to be within about 35 light years of the source.

So for now we’re probably relatively safe from that kind of death. In fact, we’re much more at risk from something in the solar system: giant explosions caused by our own sun. From now on we have to worry about asteroid impacts and then supernovae. The Cylons, despite the danger they could pose, are the least important to us, at least on this list.

“The rarity of binary neutron star mergers, combined with their narrow lethality range, means that they are probably not a serious threat to life on Earth. The researchers found that the average recurrence time for lethal mergers at the Sun’s location is much longer than the age of the universe.” he writes.

“However, even if it never results in a mass extinction event, a Kilonova event could be visible on Earth in the near future. “It will likely disrupt the technology shortly after the merger and remain bright in the sky for more than a month.”