Overview

• The Galactic Plane Survey is in its final planning phase to chart roughly 20 billion stars, about four times the total previously mapped.
• Roman’s wide-field infrared camera and filters will see through dust that dims and reddens starlight to reach the galaxy’s far side.
• By measuring how starlight is reddened at different wavelengths, scientists will infer dust grain size and composition along each line of sight.
• The resulting 3D dust maps, combined with velocity information, are expected to refine models of spiral structure and test how it influences star formation, including in the arms and central bar.
• Processed data will be released openly via the Roman Research Nexus and MAST, and the mission targets launch no later than May 2027 with a potential opportunity as soon as fall 2026.