" Jupiter's biggest moon is Ganymede, not Callisto, " she said, pointing over Ron's shoulder at a line in his Astronomy essay, " and it's lo that's got the volcanoes."
Whether Ganymede' s oceans have a similar chemical endowment is one of the biggest questions about the moon, says Leigh Fletcher, a planetary scientist at the University of Leicester, and one of the scientists working on the mission.
The ESA took the opportunity to do a test run of Juice's instruments, which it will use to look for molecular signatures of habitability on the moons Europa, Ganymede and Callisto.
欧洲航天局借此机会对 Juice 的仪器进行了测试,这些仪器将用于寻找木卫二、木卫三和木卫四上适宜居住的分子特征。
In 1610, for example, Galileo used the first telescope to discover Jupiter's moons Io, Callisto, Europa, and Ganymede — now known as the Galilean Moons.
The current count is 95 confirmed moons for Jupiter, including the largest moon in our solar system, Ganymede, which is larger than the planet Mercury.