Faint rings brought into view
Processed image. NIRCam observations from 6 February 2023 combine the 1.4- and 3.0-micron filters (F140M/F300M), assigned cyan and orange. This unannotated camera composite reveals the rings and polar brightening in near-infrared reflected light, not natural visible colour or a thermal-temperature map. Published 6 April 2023; the date is not another exposure.
NASA factual/editorial media guidelines · credited camera imagery, resized to WebP; no endorsement implied
· Original image source · Image licenceA change in observing geometry reveals a delicate planetary system.
- World
- Uranus
- Case date or period
- Camera observations · 1986 & 2023
Look closer
Voyager observed Uranus’s narrow rings and nearby moons from close range. Their faint structures become easier to trace when the source images are viewed together.
Follow the evidence
The false-colour product highlights ring differences rather than their everyday visual appearance. Its source explicitly identifies faint pastel lines between the rings as computer-enhancement artefacts. Compare the actual rings with the other observations before interpreting the smallest lines.
Heat adds a different constraint on the rings
Edward Molter, Imke de Pater, Michael Roman and Leigh Fletcher measured Uranus’s ring emission with ALMA and the Very Large Telescope. Their thermal modelling found an epsilon-ring temperature near 77 kelvin. Combining infrared and millimetre measurements helps constrain how ring particles absorb and release heat, while particle size, composition and filling factor remain uncertain. The narrow main rings have little fine dust compared with many other ring systems. Thermal emission is a physical measurement complementary to Voyager’s reflected-light photographs, not an ordinary colour image of warm-looking material.
Compare geometry before comparing brightness
Webb’s 2023 camera composite offers a much later view of the ring system than the 1986 flyby. Its near-infrared bands, assigned colours and observing geometry differ from Voyager’s clear-filter and enhanced-colour products. Follow the recognizable ring outlines across them, but do not interpret a brighter arc as newly deposited material without controlling those differences. Molter’s thermal observations answer another question about heat; the cyan and orange in this camera image are not temperature readings.
Sources & further reading
- Uranus Rings — NASA Image and Video Library / JPL
- Uranus Rings and Two Moons — NASA Image and Video Library / JPL
- Uranus Rings in False Color — NASA Image and Video Library / JPL
- Thermal Emission from the Uranian Ring System — Molter and colleagues — Original investigator research paper
- Uranus in two NIRCam filters — original unannotated Webb photograph — NASA / ESA / CSA / STScI original image release