MIT Technology Review is reporting that NASA’s Nancy Grace Roman Space Telescope is set to launch as early as the end of next month, carrying an advanced active coronagraph designed to directly image exoplanets. It said this instrument will perform one of astronomy’s most precise disappearing acts by effectively erasing most of a star’s light during photography, allowing astronomers to capture the first pictures of planets orbiting other stars that resemble those in our solar system.
The telescope, named after NASA’s first chief of astronomy, Nancy Grace Roman, will also feature a 300-megapixel wide-field camera. MIT Technology Review said this camera will capture images about 100 times larger than the Hubble Space Telescope’s widest exposures at similar resolution, aiding in the study of dark matter and dark energy. It also expects to detect around 100,000 new exoplanets. Brandon Creager, the instrument’s lead mechanical engineer at NASA’s Jet Propulsion Laboratory, expressed hope that the mission will be remembered as a critical stepping stone for finding "Earth 2.0."
Unlike previous space-based coronagraphs that use stationary systems, Roman’s active coronagraph will measure and suppress leftover starlight before each observation using two deformable mirrors. Each mirror contains 48-by-48 arrays of tiny pistons that can subtly sculpt the glass surface, creating an "active wavefront" to cancel unwanted light waves. Ilya Poberezhskiy, the instrument’s project systems engineer at JPL, compared this to noise-canceling headphones for light, creating a "doughnut-shaped region around the star where we suppress starlight and where we’re hoping to see exoplanets." This system is expected to improve sensitivity to exoplanets against stellar glare by up to 1,000 times.
The publication noted that this elaborate setup could enable the direct imaging of Jupiter analogues — planets similar in mass to Jupiter and orbiting sunlike stars at distances comparable to Earth’s orbit. Meredith MacGregor, a professor of astronomy at Johns Hopkins, highlighted the power of directly observing the planet itself rather than its effect on the star. While initial images may only show a smattering of pixels, Roman will use the coronagraph to gather information on the planet’s atmospheric chemistry, offering insights into the possibility of life. Scientists anticipate working on Roman data for decades, with its results informing NASA’s proposed Habitable Worlds Observatory, which aims to image Earthlike planets.
Full Article: Shape-shifting mirrors on NASA’s new space telescope could unveil Jupiters like our own