Jupiter

木星

Mass (Earth=1) 质量（地球=1）	318
Equatorial diameter (km) 赤道直径（公里）	143,000
Period (years) 周期（年）	11.9
Mean distance from Sun, 10⁶ km 到太阳的平均距离，10 6 km	778
Density (water=1) 密度（水=1）	1.31
Surface gravity m/s² 表面重力 m/s²	22.9

Moons

卫星

With over twice as much mass as all the other planets and moons combined, Jupiter still has 50 times too little mass to be a star. It is 318 times as massive as the Earth. It is mostly composed of hydrogen and helium, but is thought to have a heavy element core on the order of 10 times the mass of the Earth.

Jupiter 的质量是其他所有行星和卫星总和的两倍多，但仍只有足够形成恒星的五十分之一。它比地球大318倍。它主要由氢和氦组成，但被认为有一个重元素核心，其质量约为地球的十倍。

The Great Red Spot, larger than two Earths, rages like a hurricane in Jupiter's turbulent atmosphere. Heat from Jupiter's 29,700°C (53,500°F) core keeps the atmosphere churning.

大红斑，比两个地球还要大，在木星动荡的大气中像飓风一样肆虐。来自木星核心29700°C（53500°F）的热量使大气层持续翻腾。

Voyager photographs showed extensive lightning activity in the atmosphere of Jupiter, and uv photographs indicate auroral activity.

旅行者号拍摄的照片显示木星大气层中存在广泛的雷暴活动，而紫外照片表明存在极光活动。

Planetary data

行星数据

Jupiter's Moons

木星的卫星

Europa

Ganymede

Callisto

Voyager I

Name 名称	Distance from Jupiter 木星距离		Orbit Period 轨道周期	Size 尺寸
Name 名称	10⁶ m	Jupiter radii 木星半径	(days) 天数	(Longest diameter, km) （最长直径，公里）
Metis 梅蒂斯	128	1.79	0.29	40
Adastea 阿斯塔埃亚	129	1.80	0.30	20
Amalthea 阿马尔蒂亚	181	2.54	0.50	260
Thebe Thebe（专名或术语）	222	3.10	0.67	100
Io 伊奥	422	5.90	1.77	3640
Europa 欧罗巴	671	9.38	3.55	3130
Ganymede 金星	1,070	15.0	7.15	5270
Callisto 卡利斯托	1,880	26.3	16.7	4800
Leda 莱达	11,100	155	239	10
Himalia 希穆利亚	11,500	161	251	170
Lysithea 利西忒亚	11,700	164	259	24
Elara 埃尔拉	11,700	164	260	80
Ananke 安克	21,200	297	631*	20
Carme 卡迈尔	22,600	316	692*	30
Pasiphae 帕西菲埃	23,500	329	735*	36
Sinope 辛诺佩	23,700	332	758*	28

* Indicates retrograde orbit.

* 表示逆行轨道。

The four largest moons are comparable to the Earth's Moon in size. They are referred to as the Galilean moons. Their orbits are direct (in the same direction as the planet's rotation), their orbits are roughly circular, and they lie close to Jupiter's equatorial plane. Io and Europa have thick rocky mantles surrounding iron/iron sulfide cores. Ganymede and Callisto are less dense, with water and water ice accounting for as much as half of their masses. Ganymede does have a small metallic core, as evidenced by the fact that it has a magnetic field, but Callisto is apparently a largely undifferentiated mixture of rock and ice.

最大的四个卫星在大小上与地球的月球相当。它们被称为伽利略卫星。它们的轨道是直接的（与行星自转方向相同），轨道大致是圆形的，并且位于木星赤道平面附近。木卫一和木卫二有围绕铁/铁硫化物核心的厚岩层。木卫三和木卫四密度较低，水和冰占其质量的大部分，可达一半。木卫三确实有一个小的金属核心，这一点从它具有磁场这一点可以得到证明，而木卫四似乎主要由岩石和冰组成。

Additional Data for the Galilean Moons

伽利略卫星的附加数据

Name 名称	Mass (Earth moon masses) 质量（地球月球质量）	Density kg/m³ 密度 kg/m³
Io 伊奥	1.22	3500
Europa 欧罗巴	0.65	3000
Ganymede 金星	2.02	1900
Callisto 卡利斯托	1.46	1900

The outer moons are in two groups of four each at about the same orbit radius. The moons of the inner group move in eccentric, inclined orbits at about 11 million kilometers, and those of the outer group move in eccentric orbits at about 22 million kilometers which are retrograde to the planets rotation. It is likely that each group came from the breakup of a single body which was captured by Jupiter's gravity.

外侧卫星分成两组，每组四个，轨道半径大约相同。内侧组的卫星轨道是偏心且倾斜的，约在1100万公里处；外侧组的卫星轨道也是偏心的，约在2200万公里处，且方向与行星自转方向相反。很可能每组都来自一个天体的解体，该天体被木星的引力捕获。

木星及其伽利略卫星木卫一、木卫二、木卫三和木卫四的拼图。这些图像比例不准确，但展示了它们相对于木星的位置。在左上角是红色的木卫一，最靠近木星；中间是木卫二；然后是木卫三和木卫四在右下角。图片由NASA，喷气推进实验室提供。这些图像来自旅行者一号。