What would happen if we found out on very short notice that a sizable asteroid was incoming and projected to strike a major city? You might guess that it would be pretty bad news. And according to a simulation designed by NASA and run at a recent scientific conference, you’d probably be right. The fake asteroid crisis assumed that an objecting packing a thousand times as much punch as a nuclear bomb was splintered off of a larger body and wound up on a collision course with New York City. (USA Today)

In a NASA simulation of a fictional scenario, New York City was hit with an asteroid packing 1,000 times the destruction of the nuclear bomb dropped on Hiroshima.

The exercise, which was part of the “National Near-Earth Object Preparedness Strategy and Action Plan” published by the White House, played out at the the 2019 Planetary Defense Conference in College Park, Maryland, last week. It was a worst-case scenario showing what would happen if a giant space rock crashed into Earth in 2027.

Paul Chodas, the NASA engineer who designed the exercise, told AFP the simulated asteroid and its terrifying outcome is “highly unlikely” but he wanted “the issues to be exposed and discussed.”

In the interest of propriety and sensitivity, we’ll skip past all the tasteless jokes about how having SMOD strike the Big Apple might not be entirely without an upside. The point is, could we do anything about it?

In their scenario, a much larger asteroid is heading toward Earth and is projected to strike North America. Spacecraft are deployed to deflect the asteroid onto a new path, but a 60-meter fragment of it splits off and heads toward New York City. What’s the plan at that point? They concluded that there was simply nothing they could do to save New Yorkers except to evacuate them.

Two problems with this analysis immediately leap to mind. The first is the question of how we’re deflecting the larger rock. I’ve seen countless shows on the Science Channel were scientists debate the subject and offer various strategies, but as far as I know, we still don’t have any spaceships ready to do this work. And even if we did, all the projections I’ve seen indicate that you need to catch the asteroid very early and start trying to deflect it many months, if not years in advance. It takes a tremendous amount of energy to change the trajectory of something that size.

But if we can’t deflect it and it’s heading for a major metropolitan area, how much notice will we have? Calculating exactly where a space rock will land is tricky business under the best of circumstances. We may not even have a rough idea until a couple of days before impact. Do you know how long it would take to evacuate all of New York City? The New York Times examined the question back in 2005 and found that there wasn’t even a plan on record for how to do it. Under the best of circumstances, they think they might be able to move roughly three million people out of the city if you gave them three days notice. Emptying the entire five boroughs is estimated to require at least eight days, and that’s only if everything keeps ticking along perfectly the entire time.

The normal human response to an imminent threat generally boils down to a decision between fight or flight. You can’t fight an asteroid. And if you’re stuck in New York City, you probably won’t be able to take flight, either. Sleep tight, New York.