Image: The first web image of Neptune, its rings, and some of its moons. At the top left of the planet is the bright icy moon Triton. (NASA, ESA, CSA and STScI)
Some of these rings haven’t been seen since Voyager 2 flew past Neptune in 1989.
Neptune is the so-called ice giant. Compared to the gas giant planets Jupiter and Saturn, it contains elements heavier than hydrogen and helium—particularly methane, the gas that gives it its blue appearance.
This blue color is not visible in the new web image, because the space telescope looks at the universe through “infrared goggles.” Methane absorbs red and infrared light so strongly that Neptune appears completely dark in the infrared, except in places where there are high clouds.
Glacial methane clouds can be seen as bright streaks and patches that reflect sunlight before the methane absorbs them. It can also be seen in the near-infrared images of Neptune taken by the Keck telescope in recent years.
In addition to the planet itself, Webb also captured seven of Neptune’s fourteen known moons. Most notable is the large, bright icy moon Triton, which appears as a bright spot of light with diffraction peaks or “spikes” (an instrumental effect).
