Researchers from the University of California, Santa Barbara, have put forward a strategy to shield Earth from sizable asteroids, including those up to about 60 meters in diameter, whose approach could currently escape early detection. The proposal appears in a peer review publication within the field of astrophysics, and it is framed as a plan for rapid response to imminent threats rather than a long lead-time defense system.
To illustrate the concept, the team discusses the asteroid NT1, which passed at a considerable distance from Earth during the summer of 2023. They note that if a space rock were on a collision course, the explosive energy released by a direct impact would be roughly three times greater than the Chelyabinsk event in 2013, underscoring the potential severity of undetected encounters and the urgency of effective mitigations.
Past experiments have demonstrated that an asteroid’s orbit can be altered, but such interventions require the danger to be identified well before the object reaches Earth. The researchers propose a spray-like tactic designed for moments when impact is imminent but still a matter of days away. The idea is to deploy a rocket that releases a cloud replete with explosive charges and kinetic impactors aimed at the asteroid, thereby disrupting or deflecting its trajectory and breaking it into smaller fragments.
Considering typical asteroid composition and density, the fragmentation would produce pieces smaller than about 10 meters in diameter. Those fragments would be more likely to burn up in Earth’s atmosphere rather than reach the surface in significant quantities. Even if the breakup occurs only a few hours before a potential impact, the resulting debris would pose a comparatively limited risk to people on the ground.
The researchers note that modeling suggests the necessary rocket could be prepared and launched within a day, emphasizing that today’s technology is capable of supporting a planetary protection plan under rapid-response conditions. The emphasis remains on feasibility and speed, rather than on a long, drawn-out deployment that would miss a fast-approaching threat.
In their assessment, astronomers estimate that there are at least 14 thousand potentially dangerous asteroids that remain undiscovered, scattered across the solar system. This larger catalog serves as a reminder of the ongoing need for enhanced sky surveys, rapid detection pipelines, and coordinated mitigation protocols so that the proposed spray method, or similar tactics, can be deployed in a timely and controlled fashion when required. The discussion reinforces the idea that planetary defense relies on a combination of timely discovery, robust modeling, and ready-to-implement countermeasures that can be activated with minimal lead time.