NASA’s Nancy Grace Roman Space Telescope is preparing to test an advanced coronagraph designed to block starlight and directly image light reflected by distant planets. The demonstration could help establish the technology needed for a future mission capable of viewing Earth-like worlds orbiting Sun-like stars, although Roman itself is not expected to achieve that goal.

Roman’s coronagraph will use two palm-sized deformable mirrors, each with about 2,300 actuators, plus highly sensitive detectors and complex star-blocking masks to suppress a star’s glare. NASA likens the challenge to photographing a firefly beside a floodlight from across the country; engineers will test the system on known exoplanets and dusty debris discs to identify its performance and remaining technical limitations.