Scientists mark a decade of asteroid defense progress, call for more detection assets
On the tenth International Asteroid Day, experts say planetary-defense capabilities have improved but more telescopes are needed to locate hazardous near-Earth objects.
Tuesday marked the 10th anniversary of International Asteroid Day, a United Nations observance that commemorates the 1908 Tunguska event. Over the past decade, scientists say the ability to detect and mitigate potentially dangerous asteroids has advanced, yet they warn that current observation capacity remains insufficient.
Bruce Betts, chief scientist for The Planetary Society, told ABC News that without additional monitoring, “there’s an 100% chance that if we don’t do something, a dangerous asteroid will hit and people will be hurt and killed.” He added that the timing of such an impact could be tomorrow or a century from now.
According to NASA’s Office of the Inspector General, nearly 40,000 near-Earth objects have been identified as of April 2025, a fraction of which are classified as potentially hazardous. Katie Kumamoto, head of the planetary-defense group at Lawrence Livermore National Laboratory, said the biggest risk is the lack of knowledge about the full inventory of these objects.
The United States has expanded its capabilities through programs such as the Near-Earth Object Observations Program and the Double Asteroid Redirection Test (DART), which demonstrated that a spacecraft can alter an asteroid’s trajectory. However, both Betts and Kumamoto note that the number of asteroids actually visited remains very low.
To improve detection, NASA plans to launch the Near-Earth Object Surveyor space telescope in fall 2027. Using infrared sensors, the Surveyor is expected to locate at least two-thirds of potentially hazardous asteroids over a five-year mission.
Recent close approaches, such as the 2024 YR4 event that was later ruled out as a threat, illustrate the need for continuous monitoring. Scientists also highlight the upcoming 2029 flyby of asteroid Apophis, a 1,500-foot-wide rock that will pass within 20,000 miles of Earth, as a rare opportunity for study, though a dedicated NASA mission to observe it has been cancelled.
Kumamoto emphasized that while asteroids provide insight into the early solar system, they also represent a tangible planetary-defense challenge that requires sustained observation and preparedness.