First photos of Ganymede: The biggest Moon in the Solar system

NASA spacecraft Juno on Monday zoomed by just 645 miles above the surface of the solar system's largest moon Ganymede. It was the first up-close examination of Ganymede since an earlier NASA probe, Galileo, passed by in December 2000.

Ganymede is the largest of Jupiter's 79 known moons and indeed the largest moon in the entire solar system. Ganymede is more than 3,200 miles wide and is bigger than the planet Mercury. It is the only moon large enough to generate its own magnetosphere - a bubble of magnetic fields that trap and deflect charged particles from the sun.

NASA released on Tuesday two images from the flyby, revealing in remarkable detail craters, possible tectonic faults, and distinct bright and dark terrains.

One image, by the main camera, JunoCam, captured most of the dayside of Ganymede. This image is in black and white. The second image was captured by a navigation camera called the Stellar Reference Unit that can operate in low light and was able to get a clear view of the night side of Ganymede as Juno flew by.

"It will be fun to see what the two teams can piece together with the forthcoming images," said Heidi Becker, the Juno mission's radiation monitoring lead. The spacecraft will continue to send back its observations over the coming days.

NASA spacecraft Juno arrived at Jupiter on July 4, 2016. Presently it is completing its primary mission to probe the deep interior of the largest planet that orbits the sun. NASA has however extended this mission through 2025. Juno will now make 42 additional orbits of Jupiter and some of those orbits will include close flybys of Ganymede and two of Jupiter's other large moons, Io and Europa.