Paris: Astronomers have reached a significant milestone by identifying the 40,000th near-Earth asteroid (NEA), according to the European Space Agency (ESA). This achievement highlights the growing pace of asteroid detection and emphasizes the importance of planetary-defense research to address our planet's vulnerabilities.
According to Anadolu Agency, the NEA catalogue surpassed the 40,000 mark in November 2025, with a notable increase of 10,000 detections in just the past three years. NEAs consist of rocky remnants from the formation of the Solar System, with orbits that bring them within approximately 27.96 million miles (45 million kilometers) of Earth. While the first NEA, Eros, was discovered in 1898, the rate of discoveries has surged since the 1990s with the advent of dedicated survey telescopes.
Luca Conversi, manager of ESA's Near-Earth Object Coordination Centre (NEOCC), noted, "The number of discoveries is rising exponentially, from one thousand at the beginning of the century to 15,000 in 2016 and 30,000 in 2022." The introduction of advanced telescopes is expected to further accelerate the identification of NEAs.
ESA attributed the anticipated increase in NEA discoveries to two key developments: the Vera C. Rubin Observatory in Chile, which is expected to detect tens of thousands more NEAs, and ESA's Flyeye telescopes, designed to spot objects that current surveys may miss.
Once an NEA is detected, astronomers project its orbit decades or even centuries into the future. ESA's NEOCC continually updates these risk assessments. While nearly 2,000 NEAs have a non-zero chance of impacting Earth within the next century, most are small and pose no significant threat. Larger asteroids, capable of causing global destruction, are easier to detect and have largely been cataloged.
The current challenge lies in identifying asteroids between 100 and 300 meters in size, which could cause substantial regional damage. ESA estimates that only about 30% of these have been found.
Despite the vast number of known NEAs, ESA assures that none are on a collision course with Earth "for the foreseeable future." However, the agency emphasizes the importance of continued preparedness. ESA's Hera spacecraft is on its way to the asteroid Dimorphos to study the results of NASA's 2022 DART impact, a mission aimed at developing reliable asteroid deflection techniques.
ESA is also working on the Ramses mission, which will accompany the asteroid Apophis during its close, yet safe, approach in 2029. Looking further ahead, the NEOMIR infrared observatory, expected to launch in the mid-2030s, will enhance the detection of impact threats coming from the Sun's direction, similar to the 2013 Chelyabinsk event.
From the discovery of Eros over a century ago to today's global detection efforts, ESA states that each newly identified asteroid contributes to scientific understanding of the Solar System's history and bolsters humanity's capacity to protect our planet.