After devastating the French Riviera in 2013, destroying Dhaka in 2015 and saving Tokyo in 2017, an international asteroid impact simulation ended Friday with its latest disaster—New York in ruins.

Despite a simulated eight years of preparation, scientists and engineers tried but failed to deflect the killer asteroid.

The exercise has become a regular event among the international community of “planetary defense” experts.

The latest edition began Monday near Washington, with the following alert: an asteroid roughly 100 to 300 meters (330 to 1,000 feet) in diameter had been spotted and according to rough calculations had a one percent chance of hitting the Earth on April 29, 2027.

Each day during the conference, some 200 astronomers, engineers and emergency response specialists received new information, made decisions and awaited further updates from the organizers of the game, designed by a NASA aerospace engineer.

As fictional months ticked by in the simulation, the probability of the giant space rock crashing into Earth rose to 10 percent—and then to 100 percent.

NASA launched a probe in 2021 to examine the threat up close. In December that year, astronomers confirmed it was headed straight to the Denver area and that the western US city would be destroyed.

The major space powers of the United States, Europe, Russia, China and Japan decided to build six “kinetic impactors”—probes meant to hit the asteroid to change its trajectory.

It took time to build the impactors and wait for the right launch window. The impacts were set for August 2024.

Three impactors managed to hit the asteroid. The main body was deflected, but a smaller fragment broke off and continued on a deadly path, this time towards the eastern US.

Washington considered sending a nuclear bomb to deflect the 60-meter rock—repeating a successful strategy that saved Tokyo last year—but it was crippled by political disagreements.

All that remained was to prepare for impact.

With six months to go, experts could only predict that the asteroid was headed to the New York area. With two months to go, it is confirmed the city will be destroyed.

Evacuation!

The asteroid will enter the atmosphere at a blistering 69,000 kilometers per hour (43,000 miles per hour) and explode 15 kilometers (9.3 miles) above Central Park.

The energy of the blast will be 1,000 times that of the nuclear bomb dropped on Hiroshima.

It will destroy everything within a 15 kilometer “unsurvivable” radius, scientists said.

Manhattan will be completely razed. Windows as far as 45 kilometers away will shatter and damage will extend as far out as 68 kilometers from the epicenter.

The questions raised by the scenario were endless.

How do authorities evacuate ten million people? Moving people to safety from hurricanes has shown the task’s difficulty.

“Two months may not be enough time to really evacuate, because you’re evacuating people who are stuck, who have to rebuild their lives where they’re going. You’re going to have fleets of U-hauls,” said Brandy Johnson, an “angry citizen” in the exercise, referring to the rental moving trucks.

Who will pay? Who will host those displaced? How will authorities protect everything from nuclear and chemical installations to works of art?

And how will citizens behave in the face of an end-of-the-world scenario?

“If you knew your home was going to be destroyed six months from now, and that you weren’t going back again, would you keep paying your mortgage?” asked Victoria Andrews, NASA’s deputy planetary defense officer.

Participants debated insurance and legal issues at length: the United States did save Denver, but accidentally destroyed New York.

“In this situation, under international law, the United States, regardless of fault, as the launching state, would absolutely be liable to pay compensation,” said Alissa Haddaji, coordinator of a group of 15 international space lawyers created to study those very issues.

The fictional killer asteroid is, of course, “highly unlikely,” Paul Chodas, the NASA engineer who is the game’s designer, told AFP.

“But we wanted the issues to be exposed and discussed.”

Astronomers at the conference took the opportunity to defend the NeoCam space telescope project, which would help scientists better identify asteroids and react earlier to threats.

The next simulation exercise will take place in 2021 in Vienna. Chodas left open the possibility that it will be Europe’s turn in the line of fire.

© 2019 AFP

NASA, FEMA, and other national and international agencies are once again gearing up for a hypothetical asteroid impact preparedness scenario. They hope to learn the best strategies for responding to a potential strike, starting from the moment a threatening asteroid is first detected by astronomers.

Next week marks the start of the International Academy of Astronautics Planetary Defense Conference. As part of this conference, NASA’s Planetary Defense Coordination Office will team up with other partners to perform a “tabletop exercise” on how they’d handle the news of a (fictional) asteroid on a collision course with Earth.

Again, the following is fictional.

On March 26, 2019, astronomers discover an asteroid in the night sky, far dimmer than Pluto to their telescopes. They name it 2019 PDC. Initially, it appears that the asteroid’s eccentric orbit bring it within approximately 18 times the Moon’s distance from the Earth, with a chance of hitting the Earth at one in 50,000 in 2027.

Astronomers continue to track the object as it gets closer. They learn it could be somewhere between 100 and 300 meters wide—the size of a skyscraper. After a month of tracking, the probability of collision with Earth is now 1 percent—the threshold at which international organizations have agreed they must take action.

Astronomers are able to create a “risk corridor,” measuring where the asteroid might hit. Its potential paths intersect the United States, some of western Africa, and the Atlantic and the Pacific Ocean.

Though just a drill, these are the kinds of calculations that astronomers must make when a real asteroid comes close to Earth. The fictional 2019 PDC describes a “potentially hazardous asteroid,” the kind that orbits close to Earth and that could have a catastrophic impact if it actually struck the planet. Scientists recently performed a similar simulation to this one, monitoring a nearby asteroid as though it were an actual threat. The new simulation instead will focus less on the scientific questions, and more on governmental response.

This simulation is the sixth near-Earth-object impact exercise that NASA has taken part in. Not only do these exercises help NASA officials think through what they’d do in the event of a threat, but they also help them know what information is most important to FEMA and other agencies.

“What emergency managers want to know is when, where and how an asteroid would impact, and the type and extent of damage that could occur,” Leviticus Lewis of the Response Operations Division for FEMA said in the NASA press release.

We’ll be keeping track of news from the conference next week and reporting on any interesting developments. You can also follow along via a Twitter account run by the European Space Agency, @esaoperations, which will be sharing real-time updates from the exercise.