NASA's Roman telescope doubles as asteroid hunter with 300-MP camera

NASA's Nancy Grace Roman Space Telescope, set to launch from Kennedy Space Center at the end of August, has a primary mission to unravel dark matter and dark energy. But a multi-institutional team of planetary scientists is proposing a secondary role: planetary defense. Roman's 300-megapixel infrared camera boasts a field of view roughly 100 times larger than Hubble's, allowing it to scan vast swaths of the solar system while peering at distant galaxies. This unique capability lets it spot asteroids as small as 60 feet long—comparable to the Chelyabinsk meteor that injured 1,500 people in 2013. The proposal, presented at the Europlanet Science Congress, notes Roman's software currently discards asteroid streaks as noise, but minor adjustments could turn those artifacts into actionable data.

Roman's strength lies in complementing the James Webb Space Telescope (JWST). While JWST can focus intensely on individual asteroids—it helped track the 2024 YR4 threat last year—Roman's wide field can rapidly survey multiple objects, providing infrared observations of more asteroids than JWST could ever manage. This matters because NASA's Planetary Defense Coordination Office knows of roughly 25,000 near-Earth asteroids larger than 460 feet, but over half remain undiscovered. A hit from one would devastate a city. Roman could identify threats early, letting JWST or other telescopes follow up for detailed trajectory and composition analysis, and potentially enabling deflection missions. The telescope's dual-use nature also strengthens its case with lawmakers facing budget cut threats.