On August 16, 2022 an approximately 70-meter asteroid entered Earth’s atmosphere. At 2:02:10 P.M. EDT, the space rock exploded eight miles over Winston-Salem, N.C., with the energy of 10 megatons of TNT. The airburst virtually leveled the city and surrounding area. Casualties were in the thousands.

Well, not really. The destruction of Winston-Salem was the story line of the fourth Planetary Defense Tabletop Exercise, run by NASA’s Planetary Defense Coordination Office. The exercise was a simulation where academics, scientists and government officials gathered to practice how the United States would respond to a real planet-threatening asteroid. Held February 23–24, participants were both virtual and in-person, hailing from Washington D.C., the Johns Hopkins Applied Physics Lab (APL) campus in Laurel, Md., Raleigh and Winston-Salem, N.C. The exercise included more than 200 participants from 16 different federal, state and local organizations. On August 5, the final report came out, and the message was stark: humanity is not yet ready to meet this threat.

On the plus side, the exercise was meant to be hard—practically unwinnable. “We designed it to fall right into the gap in our capabilities,” says Emma Rainey, an APL senior scientist who helped to create the simulation. “The participants could do nothing to prevent the impact.” The main goal was testing the different government and scientific networks that should respond in a real-life planetary defense situation. “We want to see how effective operations and communications are between U.S. government agencies and the other organizations that would be involved, and then identify shortcomings,” says Lindley Johnson, planetary defense officer at NASA headquarters.

All in all, the exercise demonstrated that the United States doesn’t have the capability to intercept small, fast-moving asteroids, and our ability to see them is limited. Even if we could intercept space rocks, we may not be able to deflect one away from Earth, and using a nuclear weapon to destroy one is risky and filled with international legal issues. The trial also showed that misinformation—lies and false rumors spreading among the public—could drastically hamper the official effort. “Misinformation is not going away,” says Angela Stickle, a senior research scientist at APL who helped design and facilitate the exercise. “We put it into the simulation because we wanted feedback on how to counteract it and take action if it was malicious.”

Several key differences set this practice apart from previous ones in 2013, 2014 and 2016: First, this trial gave NASA’s Planetary Defense Office a chance to stress-test the National Near-Earth Object Preparedness Strategy and Action Plan, released by the White House in 2018. The plan lays out the details of who does what and when within the federal government, which allowed this year’s exercise to involve more governmental agencies than in previous years—including state and local emergency responders for the first time. The simulation was also the first to include not just an impact but its immediate aftereffects.

Events started with the “discovery” of an asteroid named “TTX22” heading toward Earth. Participants were presented with a crash course in asteroid science and told everything that was known about the asteroid and the likelihood of an impact. Each meeting jumped ahead in the timeline, with the final installments set just before and after the asteroid’s impact near Winston-Salem.    

The short but realistic timeline from discovery to impact highlighted major problems from the start. TTX22 was small and fast. By the time it was seen, it was too late to put together a mission to study, deflect or destroy it. NASA has no garages full of rockets on standby just in case an asteroid shows up. Shifting the rock’s trajectory would require at least 12 kinetic impactors, each like NASA’s DART mission that recently altered the orbit of the asteroid Dimorphos and which took more than five years to move from concept to rock-puncher. The recommendation from the after-action report on this front was blunt: develop these capabilities.

At the same time, the asteroid’s velocity, unknown composition and policy ramifications in the brief timeline ruled out hitting TTX22 with a nuclear bomb. However, late-in-the-game nuclear disruption remained an intriguing last-ditch option for some participants. “If you send up a nuclear explosive device, you could disrupt an asteroid just as it enters the atmosphere,” Stickle says. “In theory.”

That option, however, leans toward Hollywood, not reality. “There’s this tendency to think, ‘I saw this in a movie—they just launched ICBMs and blew it up,’” Johnson says. “The point of including this option in the simulation is to get them to understand that it’s not as simple. Using a nuclear explosive device in the terminal phase of an impact is a situation we don’t ever want to get ourselves into.”

Blasting an asteroid in space may result in a cluster of smaller but still-dangerous, fast-moving rocks. And an upper-atmosphere detonation of a nuclear weapon has unknown but most likely dangerous effects. The explosion may not fully disintegrate the rock, forcing portions of it down somewhere else. Radiation could persist in the upper atmosphere at levels making traveling through it on your way to space prohibitive.

With no way to stop the asteroid from hitting Earth, the exercise was all about mitigation—what must be done leading up to the impact and in the immediate aftermath. Organizations at all levels needed to be in contact, emergency plans had to be developed and enacted, and the public informed.

Within the simulated timeline, misinformation was constant. Many online news stories about the asteroid were factually incorrect, while “asteroid deniers” and claims of “fake news” grew unabated. Misinformation was a regular source of frustration for participants, who recognized that they would need to address it head-on in a real-life situation.

Johnson explained that his office is attempting to play the long game against misinformation. “We want to establish NASA’s Planetary Defense Coordination Office and those that work with us as the authorities when it comes to these situations,” Johnson says. “The plan is that the media and public understand that a group at NASA tracks and manages these types of things.”

But as participants pointed out, there are limited strategies to deal with a constant flow of lies from dozens or hundreds of outlets in a short time frame. In this case, misinformation yielded a deadly toll. “When we discussed evacuation, we were told that 20 percent of people would not leave because it was all fake news or the government was lying or some other reason,” says August Vernon, Winston-Salem/Forsyth County emergency management director. “That was about 200,000 people, all spread out. So here I am, not sure we’d even be able to evacuate the hospitals and prisons, and then we have people that can leave, refusing to leave.”

The news had a somber effect on the participants as they waited for the revelations of the simulation’s final “day,” August 16. After academic participants explained the energy release the region would experience, Vernon was blunt. “There would be collapsed buildings,” he says, “we’d lose our hospitals, a lot of our infrastructure would be gone, there was a chance this could take out cell phone reception for at least 50 miles, and the whole region would lose power.”

The simulation presented a final misinformation gut punch. Post-impact, an individual calling themselves “National Expert T.X. Asteroid” claimed the explosion released toxic materials from outer space into the atmosphere. As a result, residents should expect symptoms similar to radiation exposure. The baseless claims were all over social media, and “T.X” was giving interviews to news outlets.

On the positive side, NASA’s ability to disseminate information received high marks from participants, given the agency’s widespread credibility. In addition, the framework established in the White House plan also appeared robust enough to manage the flow of information between federal and state agencies and activate all necessary communication channels.

The conversations between federal and local officials provided some of the best results of the exercise: decision-makers at all levels reached new understandings regarding who would coordinate the post-impact rescue and recovery efforts and what they needed to do their jobs. One finding was that sometimes at the fine-grain levels, less is more in terms of communicating the science. “We couldn’t keep up sometimes, and that’s something they need to consider,” Vernon says. “I have mayors, fire chiefs and other folks to explain this to. We may not need to know all the science behind it, but we need to know what, when and where because we need to start making big decisions as early as possible.”

Participants also discovered that the face of the “expert” should change from the federal to the local level. “At our level, we asked who our lead spokesperson would be,” Vernon says. “Who would people respect, trust and believe when we find out it’s headed towards us? That might not be the same person NASA puts out there.”

Ultimately, the participants and the simulation’s facilitators agreed that the biggest thing they lacked was time. The asteroid destroyed Winton-Salem because of the narrow window between its discovery and impact. Widening that window is critical. “A decade is a fairly comfortable timeframe to be able to do something that would be effective,” Stickle says. “Thirty years would be ideal. That’s enough time for detailed observations, planning, building a spacecraft and getting something big to move. You’d even have time to send up a replacement if something goes wrong.”

There are promising signs that with enough warning, humanity could mount a successful response. The DART mission, for instance, already showed that a spacecraft’s impact can alter a space rock’s trajectory. Multiple surveys of near-Earth objects, asteroids and comets are ongoing, and NASA received $55 million more for planetary defense from Congress than it asked for.

“It’s going to take time and money to detect and characterize everything out there,” Rainey says. “As well as having the ability for missions that can get underway rapidly and be effective against something like this. But ultimately, that’s much cheaper than rebuilding a city.” But just in case, Vernon says, “At least now, we have a plan. Hopefully, it never has to be used.”