The James Webb Space Telescope (JWST) shared this detailed image of the distant icy planet Neptune with its clouds, rings and moons last week. The last time Neptune was captured in such detail was over 30 years ago when the Voyager 2 spacecraft flew across the planet. This is the only space probe to ever visit the planet.
Viewed from the Sun, Neptune is the farthest planet in the Solar System. It is thirty times farther from the sun than the Earth is from the sun. At such a large distance, the Sun is small, making a day on Neptune similar to an evening of twilight on Earth. Winds blow up to 1200 kilometers per hour. The planet is four times wider than Earth.
Neptune is actually blue because methane in Neptune’s atmosphere absorbs red light and reflects blue light. But in this image, the planet is purple because JWST is observing in infrared light. This light is invisible to the human eye. To show detail in the infrared image well, false colors were given to the image. Neptune appears relatively dark because methane absorbs infrared light. The lightest spots on the planet are thought to be clouds of methane ice, which reflect a lot of infrared light. Also clearly visible in the image are the rings of the planet.
blue spot
The bright blue spot in the upper left is not a star, but Neptune’s largest moon, Triton. A layer of nitrogen ice envelopes the moon and reflects a lot of infrared light. The six vertices around it are caused by the shape of the JWST mirror. Triton is the only large moon in the solar system that rotates in the opposite direction to the planet’s rotation.
In addition to Triton, the image shows six other moons of Neptune. Those are the little white dots between and around the rings. In total, Neptune has fourteen moons.
JWST is the largest and most powerful space telescope ever built. The device orbits the Sun at a distance of 1.5 million km from Earth.
