The next biggest moon is Callisto, at 4800 km in diameter.

第二大卫是木卫四（卡利斯托），直径约4800公里。

That means the surface is very old, maybe as old as Callisto itself.

这意味着它的表面非常古老，可能和木卫四同岁。

They're called Ganymede, Callisto, and Europa.

这几个分别叫木卫三、木卫四和木卫二。

Callisto orbits Jupiter farthest out of the four biggies, almost two million km away.

在四个大行中，木卫四的公转轨道离木，约达200万米。

The four largest moons, Io, Europa, Ganymede, and Callisto, are large enough to be seen from Earth with a telescope.

从地球上就可以用望镜看到大的四颗卫，木卫一，木卫二，木卫三，木卫四。

Juice will investigate three of the so-called Galilean moons-Callisto, Europa and Ganymede, all of which are thought to have subsurface oceans.

“果汁”探测器将调查三颗所谓的伽利略卫——木卫四、木卫二和木卫三，这三颗卫都被认为拥有地下海洋。

The new one that was huge was Callisto Protocol.

新的那个大作是《卡利сто协议》。

So we've got around Jupiter, we've got Europa, Ganymede and Callisto all seem to have the possibility of subsurface oceans.

所以在木周围，我们有欧罗巴、甘尼米德和卡利斯托似乎都有地下海洋的可能性。

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.

例如，1610 年，伽利略用第一台望镜发现了木的卫木卫一、木卫四、木卫二和木卫三，这些卫现在被称为伽利略卫。

" 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."

“木大的卫是木卫三，不是木卫四，”她从罗恩身后指着他那篇天文论文中的一行文字说道，“有火山的应该是木卫一。”

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。