Concept art of the Nancy Grace Roman Space Telescope in space, showing its large sunshield and solar panels. At the heart of Roman is a 2.4 meter primary mirror – identical to Hubble’s in size – that collects faint light from the universe. Behind that mirror is Roman’s Wide Field Instrument (WFI), a 300 megapixel camera working in visible and infrared light. In practical terms, this camera is like 18 modern Hubble detectors stitched into one enormous eye. Each Roman exposure will cover about 0.28 square degrees – roughly the area of the full Moon – about 100 times more sky than Hubble’s detectors can see at once. The result is that Roman will survey the sky up to a thousand times faster than Hubble, producing huge map-like images instead of tiny postage stamps.