NASA's Roman telescope to also hunt killer asteroids

NASA's Nancy Grace Roman Space Telescope is set to launch at the end of August 2026 from Kennedy Space Center in Florida. While its primary mission is to study dark matter and dark energy, researchers have outlined how it can also detect potentially hazardous asteroids. A team of planetary scientists and astronomers will present their findings at the Europlanet Science Congress in The Hague, Netherlands, in September 2026. They argue that Roman's wide-field infrared camera makes it uniquely suited to scan for space rocks that could threaten Earth. The telescope's 300-megapixel camera can see a patch of sky 100 times larger than the Hubble Space Telescope, allowing it to spot small asteroids up to 60 feet long. This size is comparable to the Chelyabinsk asteroid that exploded over Russia in 2013, injuring 1,500 people. According to Bryan Holler, a researcher at the Space Telescope Science Institute, the idea emerged in July 2025 when a colleague suggested demonstrating Roman's planetary defense value to lawmakers. Roman's software currently discards streaks caused by asteroids, but astronomers could modify it to identify and track these objects. Andy Rivkin, a planetary scientist at Johns Hopkins Applied Physics Laboratory, notes that while Roman's field of view is much larger than the James Webb Space Telescope's, it would complement JWST by rapidly observing multiple asteroids. Roman's infrared capabilities can estimate an asteroid's size and composition, which is crucial for assessing impact damage or deflection efforts. NASA's Planetary Defense Coordination Office is concerned with asteroids over 460 feet long, with about 25,000 estimated in near-Earth orbits and just over half still undiscovered. There are also around 230,000 asteroids 165 feet long, with less than 10 percent located. The upcoming NEO Surveyor mission, launching in 2027, will specifically hunt for these threats, but Roman can aid by refining orbits and prioritizing follow-up observations. Alise Fisher, NASA's astrophysics communications lead, says Roman's vast cosmic sampling offers opportunities for additional science. By working with telescopes like JWST and the Vera Rubin Observatory, Roman could help rule out impact risks or identify targets needing further study, contributing to planetary defense while pursuing its core astrophysics goals.