Roman Telescope's Active Coronagraph Poised to Directly Image Jupiter-Like Exoplanets

NASA's upcoming Nancy Grace Roman Space Telescope, launching next month, carries an advanced coronagraph that could directly image exoplanets similar to Jupiter, marking a key step toward finding Earth-like worlds.

This article was drafted with AI assistance from multiple sources and was reviewed and approved by a human editor before publication.

NASA's Nancy Grace Roman Space Telescope is scheduled to launch as early as the end of next month, in August 2026. The observatory will carry the first active coronagraph ever deployed in space, an instrument designed to block out starlight and reveal faint orbiting planets.

The coronagraph employs a technique called active wavefront control. Before each observation, it measures and suppresses residual starlight using two deformable mirrors. Each mirror consists of a thin glass sheet underlaid by a 48x48 grid of tiny pistons, or actuators. These actuators can push or pull the mirror surface by up to 0.5 micrometers, with increments as fine as roughly 10 picometers. According to Ilya Poberezhskiy, the coronagraph's project systems engineer at NASA's Jet Propulsion Laboratory, 10 picometers is about one-tenth the diameter of a hydrogen atom. This precision creates a doughnut-shaped region around the star where starlight is heavily suppressed, enabling the detection of exoplanets.

Compared with existing space-based coronagraphs, the new system is expected to boost sensitivity to exoplanets by as much as a factor of 1,000. That leap could allow the telescope to directly image a true Jupiter analogue—a planet with a mass similar to Jupiter's, orbiting a sunlike star at a distance several times Earth's orbital radius.

The Roman telescope also carries a wide-field camera with roughly 300 megapixels, capable of capturing images about 100 times larger than the Hubble Space Telescope's widest exposures at comparable resolution. Over its mission, Roman is expected to detect around 100,000 new exoplanets and contribute to studies of dark matter and dark energy.

Javier Viaña, a research scientist at Harvard who has two projects selected for Roman's first year of observations, described the telescope's impact in sweeping terms. He compared the transition from earlier observatories to Roman as moving from "interviewing a handful of people" to "conducting a global census."

Brandon Creager, lead mechanical engineer for the coronagraph at JPL, expressed hope about the instrument's legacy. "I hope it's remembered for it being that critical stepping stone for … finding Earth 2.0," he said.

The telescope is named after Nancy Grace Roman, who served as NASA's first chief of astronomy and was instrumental in developing the Hubble Space Telescope. To further enhance starlight suppression, the coronagraph includes masks covered with microscopic spikes known as "silicon grass" that absorb stray photons.