Amalthea 木卫五(中英对照)
Amalthea is the third of Jupiter's known satellites:
orbit: 181,300 km from Jupiter
diameter: 189 km (270 x 166 x 150)
mass: 3.5e18 kg ?
Amalthea was the nymph who nursed the infant Jupiter with goat's milk.
Discovered by Barnard 1892 September 9 using the 36 inch (91 cm) refractor at Lick Observatory. Amalthea was the last moon to be discovered by direct visual observation (as opposed to photography).
Amalthea and Himalia are Jupiter's fifth and sixth largest moons; they are about the same size but only 1/15 the size of next larger one, Europa.
Like most of Jupiter's moons, Amalthea rotates synchronously; its long axis is pointed toward Jupiter.
Amalthea is the reddest object in the solar system. The reddish color is apparently due to sulfur originating from Io.
Earlier, it was thought that its size and irregular shape should imply that Amalthea is a fairly strong, rigid body. But measurements of its mass made during Galileo's last orbit indicate otherwise. It now appears that Amalthea's density is only about the same as water and since it is unlikely to be composed of ice it is most likely a loose rubble pile with a lot of empty spaces.
Like Io, Amalthea radiates more heat than it receives from the Sun (probably due to the electrical currents induced by Jupiter's magnetic field).
Amalthea 是已知卫星中离木星第三近的一颗：
公转轨道：距木星 181,300 千米
卫星直径：189 千米（270×166×150）
质量：7.17e18 千克
Amalthea是一位用山羊奶照顾朱比特成人的仙女。
它于1892年9月9日由Barnard于Lick天文台用36英尺（91厘米）折射望远镜发现。木卫五是最后一颗直接用视觉观察发现的卫星（相对于摄相而言）。
木卫五与木卫六是木星第五与第六大卫星，它们的大小是第四大卫星木卫二的15分之一。
像大多数的木星卫星，木卫五同步自转，它的长轴直指木星。
木卫五是太阳系中最红的物体。红色可能是由木卫一发出的含硫物质造成的。
它的大小及不规则外形意味着它是一个相当坚硬的物体。它的组成更像是一颗小行星而不是伽利略类的卫星。
与木卫一类似，木卫五辐射出的热量比从太阳处收到的多（可能是因为木星磁场感应出的电流的关系）。
