Free Astronomy Magazine November-December 2022

44 NOVEMBER-DECEMBER 2022 ASTRO PUBLISHING N ASA’s James Webb Space Tele- scope shows off its capabili- ties closer to home with its first image of Neptune. Not only has Webb captured the clearest view of this distant planet’s rings in more than 30 years, but its cameras reveal the ice giant in a whole new light. Most striking in Webb’s new image is the crisp view of the planet’s rings – some of which have not been de- tected since NASA’s Voyager 2 be- came the first spacecraft to observe Neptune during its flyby in 1989. In addition to several bright, narrow rings, the Webb image clearly shows Neptune’s fainter dust bands. “It has been three decades since we last saw those faint, dusty bands, and this is the first time we’ve seen them in the infrared,” notes Heidi Hammel, a Neptune system expert and interdisciplinary scientist for Webb. Webb’s extremely stable and precise image quality permits these very faint rings to be detected so close to Neptune. Neptune has fascinated researchers since its discovery in 1846. Located 30 times farther from the Sun than Earth, Neptune orbits in the remote, dark region of the outer solar sys- tem. At that extreme distance, the Sun is so small and faint that high noon on Neptune is similar to a dim twilight on Earth. Webb’s clearest image of Neptune’s rings by NASA/ESA/CSA Hannah Braun Christine Pulliam I n this image by Webb’s Near-Infrared Camera (NIRCam), a smattering of hundreds of back- ground galaxies, varying in size and shape, appear alongside the Neptune system. Neptune, when compared to Earth, is a big planet. If Earth were the size of a nickel, Neptune would be as big as a basketball. In most portraits, the outer planets of our solar system reflect this other- worldly size. However, Neptune appears relatively small in a wide-field view of the vast uni- verse. Towards the bottom left of this image, a barred spiral galaxy comes into focus. Scientists say this particular galaxy, previously unexplored in detail, may be about a billion light-years away. Spiral galaxies like this are typically dominated by young stars that appear blueish in these wavelengths. [NASA, ESA, CSA, STScI − Image processing: Joseph DePasquale (STScI)]