New Webb Image Captures Clearest View of Neptune’s Rings in Decades
By NASA Laura Betz (Goddard Space Flight Center, Greenbelt, MD), Hannah Braun and Christine Pulliam (Space Telescope Science Institute, Baltimore, MD).
Excerpt: ...Webb’s extremely stable and precise image quality permits these very faint rings to be detected so close to Neptune. ...Compared to the gas giants, Jupiter and Saturn, Neptune is much richer in elements heavier than hydrogen and helium. This is readily apparent in Neptune’s signature blue appearance in Hubble Space Telescope images at visible wavelengths, caused by small amounts of gaseous methane. Webb’s Near-Infrared Camera (NIRCam) images objects in the near-infrared range from 0.6 to 5 microns, so Neptune does not appear blue to Webb. In fact, the methane gas so strongly absorbs red and infrared light that the planet is quite dark at these near-infrared wavelengths, except where high-altitude clouds are present. Such methane-ice clouds are prominent as bright streaks and spots, which reflect sunlight before it is absorbed by methane gas.…