Imagine that researchers discover a giant asteroid that has a 72% chance of hitting Earth in 14 years — a space rock so massive it could destroy an entire city and wreak havoc across a vast area.
Recently, NASA experts, government emergency managers and international partners examined this catastrophic scenario. According to a new NASA report, they conducted a tabletop simulation to strengthen the nation's preparedness for potential asteroid threats.
Although there is no immediate threat, NASA's experiment underscores how unprepared humanity is for a potential asteroid strike of this magnitude.
When was this exercise conducted?
According to an official report released by NASA, the agency held its fifth biennial Planetary Defense Interagency Tabletop Exercise at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland in April. On June 20, NASA provided a detailed summary of the exercise.
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What did NASA learn from this exercise?
Although no serious asteroid threat is currently expected, the exercise was intended to assess Earth's response capabilities in the unlikely event of a potentially catastrophic asteroid impact.
“So far, we don't know of any large asteroids that could pose a threat to Earth in the next century,” reassured Terrick Daly, supervisor of planetary defense at the Johns Hopkins Applied Physics Laboratory. However, Daly added, “we also know that we haven't identified most of the asteroids large enough to cause regional devastation.”
The uncertainties in the exercise's starting conditions allowed participants to tackle particularly challenging scenarios, said Lindley Johnson, planetary defense officer emeritus at NASA Headquarters in Washington. “Perhaps the only natural disaster that humanity can anticipate years in advance and take action to prevent is a large asteroid impact,” he added.
Data from the exercise, conducted in April in Laurel, Maryland, shows that astronomers estimate there are about 25,000 “near-Earth objects” that are 140 meters or larger. However, only 43 percent of these have been detected so far.
NASA report: Three conclusions
Planetary defense experts conduct routine exercises every few years, including simulations like this one. These exercises follow the success of NASA's DART mission, which demonstrated that a spacecraft's trajectory could change if it collided with an asteroid. The latest scenario considered asteroids ranging from 60 to about 800 meters in diameter.
However, initial observations during the exercise were not sufficient to accurately determine the asteroid's size, composition, or long-term trajectory. Participants evaluated three options:
- Wait for additional telescopic observations.
- Launch a US-led mission to collect more data.
- Build a spacecraft to spend time near the asteroid and potentially alter its trajectory.
Unlike previous simulations, this one did not have a spectacular outcome. According to Daly, “we stayed focused on one scenario throughout the entire exercise,” which allowed for discussion of funding, communications, urgency, and practical issues.
The research shows that there is uncertainty about the availability of funding without more accurate risk information. Technical experts initially assumed funding would not be an issue, but “cost was definitely a concern,” Daly explains.
In the meantime, NASA plans to launch a new telescope aimed at identifying asteroids in the fall of 2027. “We'll have to figure out what's out there, determine their orbits and assess their potential impact risks to Earth over time,” Johnson explained.