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Most people are aware that an asteroid wiped out much of life on Earth around 65 million years ago, and this knowledge contributes to that chill of fear that many people experience, at least occasionally, that something like this could happen again. The science is clear that it could happen again, but how likely is it to happen in the average person's lifetime?

A , appearing on the preprint server arXiv and soon to be published in the Planetary Science Journal, has conveniently laid out the likelihood of dying from a variety of (mostly) preventable deaths and compared these to the likelihood of dying from an asteroid impact.

Carrie Nugent and her group wanted to put these odds into perspective for the general public, as these probabilities have been calculated before, but can be hard to understand without context. This work also provides a framework for policymakers to prioritize planetary defense and encourage funding for asteroid detection and deflection missions if need be.

For this study, the researchers used a simulation of 5 million near-Earth objects (NEOs) with diameters greater than 140 meters. They simulated the NEO orbits and counted Earth impacts over 150 years to determine how likely it is for an NEO to hit Earth. These results were then compared to the probabilities of other unfortunate events to happen to individuals during a 71-year lifetime, including things like lightning strikes, elephant attacks, and carbon monoxide poisoning, and how likely a person was to die from these events.

They found an estimated impact frequency for NEOs greater than 140 meters in size is about one every 11,000 years. Of course, there is a big difference between the fatality rate of a 140-meter-wide asteroid and one that is 10 kilometers wide. The effects would also depend on many other factors, like where it lands and the velocity at which it hits Earth.

The researchers note that a 140−200 meter NEO landing in the ocean might have zero fatalities, while a 180−200 meter NEO has a chance of affecting a million people if it hits a highly populated area, and even larger NEO impacts can affect the entire world. So, even if a NEO hit Earth, there is still a good chance that most people would survive if it were on the smaller end.

The study results also show how likely each event is to kill a person when it does occur. They found that things like carbon monoxide poisoning and elephant attacks are much more likely to kill a person when they do occur. And, although it is extremely rare, those involved in dry sand hole collapses almost always die.

When comparing the likelihood of asteroid events to other possible events, some of the results might be surprising. For example, the chance of a >140 meter asteroid hitting Earth is more likely than an individual being struck by lightning in their lifetime and more likely than an individual being attacked by a coyote. On the other hand, it is probably not that surprising that an individual is much more likely to catch the flu or get into a car accident during their lifetime than to experience an asteroid hitting Earth.

There is hope that works like this can contextualize these risks and help the public understand why planetary defense is important, even if NEO events are rare. The researchers point out the importance of programs like the Double Asteroid Redirection Test (DART) Mission, which demonstrated that humans can design spacecraft with the ability to deflect asteroids headed for Earth.

They note the National Academies report discussing planetary defense from asteroids, saying, "The committee considers work on this problem as insurance, with the premiums devoted wholly toward preventing the tragedy."

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