NASA's big statement on the asteroid threat, no large asteroids identified that could cause damage, but if it happens…

Imagine if scientists discovered a massive asteroid with a 72% chance of hitting Earth in 14 years: a space rock so big it could wipe out a city and wreak havoc on an entire region.

That's the hypothetical scenario that NASA experts, federal emergency officials and their international partners recently explored. They conducted a tabletop simulation to strengthen the nation's preparedness for future asteroid threats, according to a new NASA report.

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NASA's big statement on the threat of asteroids

Terik Daly, supervisor of planetary defense at the Johns Hopkins Applied Physics Laboratory, reassures us: “At this time, we do not know of any large asteroids that would pose a threat to Earth for the next century.” However, Daly adds, “we also know that we have not identified most of the asteroids large enough to cause regional devastation.”

Astronomers estimate that about 25,000 “near-Earth objects” are 140 meters or larger, but only about 43 percent have been discovered so far, according to data from the April exercise in Laurel, Maryland.

NASA Asteroid Preparedness Report

This simulation is part of a series of exercises that planetary defense experts perform every few years. It follows NASA's DART mission, which demonstrated that a spacecraft could change the trajectory of an asteroid by colliding with it. In the latter scenario, scientists estimated the size of the asteroid between 60 meters and almost 800 meters in diameter. Even a smaller asteroid in this range could cause significant damage if it fell near a populated area, says Lindley Johnson, a former NASA planetary defense officer.

Daly highlights the challenge: “We view the asteroid as a bright point in space, which leads to great uncertainties about its properties and the potential consequences of its impact.” Additionally, this exercise assumed that scientists would not be able to collect more data for six months until the asteroid was observable again, adding to the uncertainty.

Asteroid threat to Earth: the three options

Participants considered three options: wait for more telescope observations, launch a U.S.-led mission to gather information, or build a spacecraft to spend time near the asteroid and potentially change its trajectory. Unlike previous simulations, this one did not lead to a dramatic conclusion. “We were locked in for the entire exercise,” Daly says, giving us time to discuss communication, urgency, funding and practical considerations.

The report notes skepticism about the availability of funding without more definitive knowledge of the risks. Daly points out that technical experts previously thought funding wouldn't be an issue, but that “cost was absolutely a concern.”

FEMA's LA Lewis highlights the challenge for emergency managers of balancing resources for a distant threat while dealing with immediate dangers like tornadoes and hurricanes.

Meanwhile, NASA plans to launch a new asteroid-detecting telescope in fall 2027. “We need to find out what's out there, determine their orbits, and assess their risk of impacting Earth over time. time,” Johnson says.