What would we do if an asteroid slammed Earth on July 12, 2038?

NASA's latest asteroid impact dry run revealed humanity may be our biggest hurdle.
Concept art of asteroid entering planet's atmosphere
A proposed scenario gave emergency experts 14 years to plan for a potential asteroid impact on Earth. Image: Deposit Photos

Here’s the scenario: The government has confirmed NASA astronomers detected a never-before-seen asteroid speeding in the direction of Earth—and although it will take 14 years to arrive, there is a 72-percent chance it will directly strike the planet on July 12, 2038. With what little information is known, observers believe its diameter could be anywhere from 80-800 meters (262-2624 feet) wide. Either way, it’s enough to cause cataclysmic death and destruction. And to make the situation even worse, experts won’t be able to conduct additional critical assessments for at least the next seven months while the rock passes behind the Sun as seen from Earth. What do you do?

That’s the hypothetical dilemma recently put forth by NASA and FEMA during the fifth biennial Planetary Defense Interagency Tabletop Exercise, held at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland. Although completed in April, NASA just released its initial summary on June 20, with additional plans to make a “complete after-action report” available later this year.

Screenshot from NASA Planetary Defense Interagency Tabletop Exercise showing fictional asteroid impact path
A screenshot from NASA’s tabletop exercise shows just how difficult it may be to predict an asteroid’s landing site. Credit: NASA

Catastrophic asteroids and comets strikes on Earth are rare but inevitable. While it’s disconcerting to consider that another hit is almost certainly in the planet’s forecast, there is at least a small silver lining compared to other major environmental emergencies.

“A large asteroid impact is potentially the only natural disaster humanity has the technology to predict years in advance and take action to prevent,” NASA planetary defense officer emeritus Lindley Johnson said in the agency’s announcement on Thursday.

Knowing this, roughly 100 representatives from government agencies, companies, and watchdog organizations including the US State Department, Smithsonian Institute, European Space Agency, and the University of Cambridge met this spring over two days in Maryland. While there, they outlined the current international authorities’ strengths and weaknesses in the face of such a major global uncertainty. Unlike previous space disaster tabletop exercises, however, the team had a vital new resource at their disposal—data from NASA’s Double Asteroid Redirection Test (DART) mission.

After a 7-million-mile journey, a car-sized, $325 million DART spacecraft intentionally impacted a 525-feet-wide asteroid moonlet called Dimorphos while it orbited its parent meteor, Didymos, on September 26, 2022. Although NASA previously estimated DART only had about a 10 percent chance of success, the craft managed to stick its fatal landing while traveling about 14,000 mph, creating a wide crater and ejecting 2 million pounds of debris into space in the process. Despite originally likening the procedure to “running a golf cart into a Great Pyramid,” the DART mission managed to permanently alter the path of Dimorphos, turning a wild science-fiction concept into a reality.

Armed with copious amounts of information from DART, the crisis scenario team set to work on determining what international cooperative efforts can and can’t currently accomplish in the face of an impending asteroid strike. While participants noted that “timelines of space mission planning, disaster management, information sharing, and communications are intertwined in ways that were not fully appreciated at first,” they established a general outline of an ideal response plan ahead of the hypothetical 2038 impact date.

DART closeup of Dimorphos asteroid on NASA live tv
The final seconds of impact, caught on DART’s live camera on September 26, 2022. Credit: NASA

After waiting for more information following the asteroid reemerging from behind the Sun, team members determined to first plan a $200-$400 million flyby mission led by NASA, along with encouraging similar missions from international space agencies. Once concrete data and trajectories could be established, a second $800 million-to-$1 billion “purpose-built rendezvous” mission—basically, a DART successor on steroids to shove the asteroid out of Earth’s path.

Of course, experts acknowledge a mountain of hurdles to overcome amid international coordination efforts. One of the main domestic issues would be the likelihood that the US Congress would be “unlikely to act until impact is certain.” Similarly, funding in general to prevent the possible tragedy may be hard to coax from governments until convincing evidence of an impending threat is presented—an obvious issue, given that time would be of the essence, even with a 14-year heads up. And then there’s the all-but-certain tidal waves of dis- and misinformation to debunk for the public.

[Related: 5 ways we know DART crushed that asteroid (but not literally)]

Another limiting factor is that a “kinetic impact” mission like DART is the only potential remedy that’s been fully tested in space. Experts stressed that it’s in humanity’s best interests that additional possible solutions are researched and demonstrated, such as ion beam technology.

Despite the many challenges, post-exercise participant surveys were somewhat positive. Nearly 75-percent of respondents believe humanity is already adequately ready to conduct the necessary reconnaissance missions. That said, barely half of those surveyed reportedly think international leaders are prepared to carry out Earth impact prevention missions.

At the very least, future projects are already in the works to further our understanding and readiness of potential space collisions. NASA is currently developing its Near-Earth Object (NEO) Surveyor, an infrared telescope intended to focus specifically on discovering, classifying, and characterizing potentially hazardous space rocks years ahead of becoming threats. The NEO Surveyor is on track to launch in June 2028, while additional tabletop exercises are already in the works to continue training emergency experts on how to best deal with such a terrifying—and unfortunately possible—situation.