A Striking Crater on Jupiter's Moon Ganymede
This look at the complex surface of Jupiter's moon Ganymede came from NASA's Juno mission during a close pass by the giant moon in June 2021. At closest approach, the spacecraft came within just 650 miles (1,046 kilometers) of Ganymede's surface.
Most of Ganymede's craters have bright rays extending from the impact scar, but about 1 percent of the craters have dark rays. This image taken by JunoCam during the close Ganymede pass shows one of the dark-rayed craters. The crater, named Kittu, is about 9 miles (15 kilometers) across, surrounded by darker material ejected during the impact that formed the crater. Scientists believe that contamination from the impactor produced the dark rays. As time passes, the rays stay dark because they are a bit warmer than the surroundings, so ice is driven off to condense on nearby colder, brighter terrain.
Ganymede is the largest moon in our solar system, larger even than the planet Mercury. It's the only moon known to have its own magnetic field, which causes auroras that circle the moon's poles. Evidence also indicates Ganymede may hide a liquid water ocean beneath its icy surface.
Citizen scientist Thomas Thomopoulos created this enhanced-color image using data from the JunoCam camera. The original image was taken on June 7, 2021.
JunoCam's raw images are available for the public to peruse and process into image products at https://missionjuno.swri.edu/junocam/processing. More information about NASA citizen science can be found at https://science.nasa.gov/citizenscience and https://www.nasa.gov/solve/opportunities/citizenscience.
More information about Juno is at https://www.nasa.gov/juno and https://missionjuno.swri.edu. For more about this finding and other science results, see https://www.missionjuno.swri.edu/science-findings.