A new image from the JunoCam instrument aboard NASA’s Juno spacecraft shows a large crater on Ganymede, the Jupiter’s largest moon.
This image of Ganymede was captured by NASA’s Juno mission during a close flyby in June 2021. The enhanced-color version of the image was created by citizen scientist Thomas Thomopoulos. Image credit: NASA / JPL-Caltech / SwRI / MSSS / Thomas Thomopoulos.
Ganymede, the largest moon in our Solar System, has a diameter of 5,268 km (3,273 miles).
It is around 8% larger than that of the planet Mercury and much larger than Pluto.
Discovered in 1610, Ganymede is the only moon in the Solar System to have its own magnetosphere, which causes aurorae in regions circling its north and south poles.
As the giant moon has no atmosphere, the surface at its poles is constantly being bombarded by plasma from the magnetosphere of Jupiter. This bombardment has a dramatic effect on the moon’s ice.
Evidence also indicates Ganymede may hide a liquid water ocean beneath its icy surface.
On June 7, 2021, NASA’s Juno probe successfully made a close flyby of Ganymede.
At the time of closest approach, the spacecraft was 1,038 km (645 miles) above the moon’s surface.
“Most of Ganymede’s craters have bright rays extending from the impact scar, but about 1% of the craters have dark rays,” members of the Juno team said.
“The new image taken by the JunoCam imager during the close Ganymede pass shows one of the dark-rayed craters.”
“The crater, named Kittu, is about 15 km (9 miles) across, surrounded by darker material ejected during the impact that formed the crater,” they added.
“We 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.”
