Astronomers unlock a sharper view from JWST using a 'keyhole' trick: A revived technique could reveal planets near their stars and the inner workings of galaxies.

The article focuses on the use of a revived interferometric technique with NASA's James Webb Space Telescope (JWST) to enhance its resolution for studying closely spaced astronomical objects. This method employs the Aperture Masking Interferometer (AMI), a 5-centimeter-wide metal disk with holes installed in JWST’s Near-Infrared Imager and Slitless Spectrograph (NIRISS), which turns the telescope’s mirror into a mini-interferometer. Initial challenges due to infrared detector limitations were overcome by developing a detailed forward model simulating the entire system, enabling reconstruction of high-resolution images such as volcanic activity on Jupiter’s moon Io and jets from black holes. The technique holds promise for directly imaging exoplanets near their stars, particularly in regions inaccessible to JWST’s coronagraph, potentially advancing the study of planetary atmospheres and compositions. [Extracted from the article]