“We anticipate that this will be recognized as a crucial milestone in our quest for Earth 2.0,” stated Brandon Krieger, the lead mechanical engineer at NASA’s Jet Propulsion Laboratory (JPL).
The innovative Nancy Grace Roman Telescope, named after NASA’s pioneering director of astronomy, boasts an impressive 300-megapixel wide-field camera. This cutting-edge technology will capture images roughly 100 times wider than those from the Hubble Space Telescope, while maintaining similar resolution.
These groundbreaking features are poised to assist astronomers in unraveling the mysteries of dark matter and dark energy. The telescope is expected to identify over 100,000 exoplanets—celestial bodies beyond our solar system. Their existence can be inferred by observing how they distort the light from distant stars. Research scientist Javier Viaña from Harvard University compares this new capability to transitioning from “interviewing a small number of people” to “conducting a global census.”
Additionally, another advanced camera features a coronagraph, which effectively blocks out starlight, enabling the observation of one star system at a time. This technology empowers astronomers to gain unprecedented insights into the universe, allowing for the detection of smaller, fainter, and closer exoplanets. Krieger emphasizes, “This technology permits us to discover planets that were previously impossible to detect.”
Innovative Structure of the Coronagraph
While coronagraphs are not a novel concept in space exploration, earlier telescopes, including those aboard Hubble and the James Webb Space Telescope, relied on anchoring systems to obstruct the intense light of stars. Although effective, this method resembles covering a flashlight with your thumb while searching for fireflies in a dimly lit room. Bright light can still leak out, masking the faint light from distant planets. Within a telescope, this glare can stem from light escaping through the device’s edges or imperfections in its mirrors.
In contrast, Roman’s coronagraph employs a groundbreaking method previously unseen in space telescopes until this year. It will measure residual light prior to observations and actively suppress it, using a technique called active wavefront control.
This is made possible by the telescope’s dual deformable mirrors. Each actuator, resembling tiny pistons, is arranged in a 48 × 48 checkerboard pattern beneath a thin glass layer. A slight voltage retraction of the actuators enables intricate adjustments of the mirror surface, akin to thousands of microscopic fingers delicately sculpting the structure.
The adjustments are remarkably fine; each mirror section can deform by up to 0.5 micrometers, equivalent to about a quarter of the mirror’s size. This level of precision rivals that of Escherichia coli bacteria in small increments of approximately 10 picometers—about one-tenth the diameter of a hydrogen atom, as noted by Ilya Poveretsky, project systems engineer for the device at JPL.
Source: www.technologyreview.com