Ganymede appears to have a number of ocean layers, stacked up with layers of ice between them. The best level of ice may be the crust, which could be about 150 kilometers (about 90 miles) thick. The lowest ocean degree could be 800 kilometers (about five hundred miles) beneath that, https://best-moons25791.daneblogger.com/33752783/best-moons-things-to-know-before-you-buy