With its first image of Neptune, NASA's James Webb Space Telescope (JWST) provides the best glimpse of the planet's rings in more than 30 years. It also shed new insight on the ice giant.
Neptune's New Photos Captured by the James Webb Space Telescope
The NASA Solar System Twitter account has revealed the best image of the Neptune rings in a new post. The caption reads, "We're always big fans of Saturn, but Neptune's rings are giving us all the feels in this new image."
NASA's Voyager 2 exploration to Neptune in 1989 was not able to detect some of the planet's rings. Yet, with the new photo from JWST, we can have a crispier view of the ring and fainter dust bands in addition to many brilliant, narrow rings.
Voyager 2 made its closest approach to any planet since leaving Earth 12 years ago, passing 4,950 kilometers (3,000 miles) above Neptune's north pole, according to NASA.
This is the first time that these faint, dusty rings in the infrared have been observed, according to Heidi Hammel, an expert on the Neptune system and transdisciplinary scientist for Webb. It has been thirty years since we last saw them. These faint rings were discovered so close to Neptune because of Webb's exceptionally consistent and accurate image quality.
Neptune Chemical Composition
It orbits in the distant, dark area of the outer solar system, which is 30 times further from the Sun than Earth. High noon on Neptune is comparable to a dull twilight on Earth because of how small and pale the Sun appears from such a great distance away.
The internal chemical composition of Neptune qualifies it as an ice giant. It is substantially richer in elements heavier than hydrogen and helium than the gas giants Jupiter and Saturn. The gaseous methane's small concentrations enable Neptune to appear blue in Hubble Space Telescope photos at visible wavelengths.
Neptune does not appear blue to Webb because the Near-Infrared Camera (NIRCam) only sees objects in the near-infrared spectrum between 0.6 and 5 microns. In fact, the planet is fairly black at these near-infrared wavelengths due to the substantial absorption of red and infrared light by methane gas, with the exception of areas with high-altitude clouds.
The bright streaks and spots of methane-ice clouds are noticeable because they reflect sunlight before it is absorbed by methane gas.
A more discrete visual indicator of the global atmospheric circulation that fuels Neptune's winds and storms could be the thin line of brightness circling the planet's equator. At the equator, the atmosphere lowers and warms, which causes it to glow at infrared wavelengths more than the nearby cooler gases.
Neptune Features
Neptune's northern pole is out of sight for astronomers due to its 164-year orbit. However, the Webb images suggest an unusual brightness there. Webb's image shows a previously known vortex around the southern pole. Neptune is dominated by an extremely bright point of light with the unique diffraction spikes seen in many of Webb's pictures. However, this is the first time that the telescope has shown a continuous band of high-latitude clouds surrounding it.
The telescope also captured seven of the 14 known moons of Neptune. A very brilliant point of light with the distinctive diffraction spikes observed in many of Webb's photographs dominates this Webb painting of Neptune. It also shows an object that looks like a star, but it is Triton, the big moon of Neptune. Triton reflects an average of 70% of the light that it receives thanks to its frozen condensed nitrogen sheen.
