NASA’s Juno probe has just delivered the closest images of Jupiter’s icy moon Ganymede that we have seen in decades, offering up some incredible glimpses of its surface.
Ganymede is the biggest moon in the Solar System (even larger than Mercury) and the only one with its own magnetic field. It has an iron-rich core and an internal ocean with possibly more water than all the oceans on Earth. It’s definitely a world worth studying.
Juno’s main mission is to peer inside Jupiter, and it has provided us with some spectacular images of the gas giant, but during its flybys, it has also looked at its many moons. On June 7, Juno flew over Ganymede snapping several portraits. The first one here taken by JunoCam shows the icy surface from a single green filter revealing craters and maybe even tectonic features. The image resolution is about 1 kilometer (0.6 miles) per pixel.
JunoCam captured almost the entire side of the water-ice encrusted moon. “This is the closest any spacecraft has come to this mammoth moon in a generation,” Juno Principal Investigator Scott Bolton said in a statement. “We are going to take our time before we draw any scientific conclusions, but until then we can simply marvel at this celestial wonder.”
Color images will also soon be created from the data by NASA experts using red and blue filters, which will provide a color portrait of the moon.
Juno also delivered a very cool view of the night side of the moon where the light bouncing off Jupiter was enough to illuminate Ganymede for Juno’s Stellar Reference Unit, which is a navigation camera.
“The conditions in which we collected the dark side image of Ganymede were ideal for a low-light camera like our Stellar Reference Unit,” said Heidi Becker, Juno’s radiation monitoring lead. “So this is a different part of the surface than seen by JunoCam in direct sunlight. It will be fun to see what the two teams can piece together.”
Juno will be sending back more images of its flyby in the next few days, which are available here as raw images, so it's just a matter of time for image experts to polish up these pictures and we should get some more spectacular views of Ganymede.