宇宙相关知识.doc

在英文中，大行星都是以罗马神话中神的名字来命名的。分别是： 水星：神使墨丘利（Mercury）； 金星：爱神维纳斯（Venus）； 地球：大地之神垓娅（Earth）； 火星：战神玛尔斯（Mars）； 木星；主神朱庇特（Jupiter）； 土星：农神萨图恩（Saturn）； 天王星：朱庇特的祖父，第一代天神乌拉诺斯（Uranus）； 海王星：海神尼普顿（Neptune）； 附加一个现在是矮行星的冥王星：冥神普路托（Pluto）。太阳系是由受太阳引力约束的天体组成的系统，它的最大范围约可延伸到1光年以外。太阳系的主要成员有：太阳（恒星）、八大行星（包括地球）、无数小行星、众多卫星（包括月亮），还有彗星、流星体以及大量尘埃物质和稀薄的气态物质.在太阳系中，太阳的质量占太阳系总质量的99.8%，其它天体的总和不到有太阳的0.2%。太阳是中心天体，它的引力控制着整个太阳系，使其它天体绕太阳公转，太阳系中的九大行星（水星、金星、地球、火星、木星、土星、天王星、海王星）都在接近同一平面的近圆轨道上，朝同一方向绕太阳公转。 距离(AU) 半径(地球) 质量(地球) 轨道倾角(度) 轨道 偏心率 倾斜度 密度(g/cm3) 太阳 0 109 332,800 - - - 1.410 水星 0.39 0.38 0.05 7 0.2056 0.1 5.43 金星 0.72 0.95 0.89 3.394 0.0068 177.4 5.25 地球 1.0 1.00 1.00 0.000 0.0167 23.45 5.52 火星 1.5 0.53 0.11 1.850 0.0934 25.19 3.95 木星 5.2 11.0 318 1.308 0.0483 3.12 1.33 土星 9.5 9.5 95 2.488 0.0560 26.73 0.69 天王星 19.2 4.0 17 0.774 0.0461 97.86 1.29 海王星 30.1 3.9 17 1.774 0.0097 29.56 1.64 八大行星中，一般把水星、金星、地球和火星称为类地行星，它们的共同特点是其主要由石质和铁质构成，半径和质量较小，但密度较高。把木星、土星、天王星和海王星称为类木行星，它们的共同特点是其主要由氢、氦、冰、甲烷、氨等构成，石质和铁质只占极小的比例，它们的质量和半径均远大于地球，但密度却较低。 远计算，行星到太阳的距离（用a表示）a=0.4+0.3*2n-2（天文单位）其中n表示由近到远第n个行星（详见上表） 地球、火星、木星、土星、天王星、海王星的自转周期为12小时到一天左右，但水星、金星自转周期很长，分别为58.65天、243天和6.387天，多数行星的自转方向和公转方向相同，但金星则相反。 除了水星和金星，其它行星都有卫星绕转，构成卫星系。 在太阳系中，现已发现1600多颗彗星，大多数彗星是朝同一方向绕太阳公转，但也有逆向公转的。彗星绕太阳运行中呈现奇特的形状变化。 太阳系中还有数量众多的大小流星体，有些流星体是成群的，这些流星群是彗星瓦解的产物。大流星体降落到地面成为陨石。 太阳系是银河系的极微小部分，它只是银河系中上千亿个恒星中的一个，它离银河系中心约8.5千秒差距,即不到3万光年。太阳带着整个太阳系绕银河系中心转动。可见，太阳系不在宇宙中心，也不在银河系中心。 太阳是50亿年前由星际云瓦解后的一团小云塌缩而成的，它的寿命约为100亿年。By the sun in the solar system by gravitational bound by the celestial bodies formed, to the maximum extent it can be extended to about 1 light-years away. The main members of the solar system: the sun (star), the eight planets (Earth), numerous asteroids, a large number of satellites (including the moon), comets, meteoroid and a large amount of dust material and thin gaseous material. In the solar system, the sun The quality of the solar system accounted for 99.8 percent of the total mass, and other celestial bodies are less than the sum of 0.2 percent of the sun. Sun is the Center for Astrophysics, which controls the gravity of the solar system as a whole, so that other celestial bodies around the sun, the solar systems nine planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune) are close to the same plane near Circular orbit, in the same direction around the sun. Distance (AU) radius (Earth) quality (Earth) orbit inclination angle (degrees) orbital eccentricity gradient density (g/cm3) Sun 0 109 332,800 - - - 1.410 Mercury 0.39 0.38 0.05 7 0.2056 0.1 5.43 Venus 0.72 0.95 0.89 3.394 0.0068 177.4 5.25 Earth 1.0 1.00 1.00 0.000 0.0167 23.45 5.52 Mars 1.5 0.53 0.11 1.850 0.0934 25.19 3.95 Jupiter 5.2 11.0 318 1.308 0.0483 3.12 1.33 Saturn 9.5 9.5 95 2.488 0.0560 26.73 0.69 Uranus 19.2 4.0 17 0.774 0.0461 97.86 1.29 Neptune 30.1 3.9 17 1.774 0.0097 29.56 1.64 Eight planets, the general Mercury, Venus, Earth and Mars as the terrestrial planets, their common feature is its stone and iron from the main structure, and quality of the smaller radius, but a higher density. The Jupiter, Saturn, Uranus and Neptune known as the Jovian planets, their common feature is mainly hydrogen, helium, ice, methane, ammonia, etc., stone and iron accounted for only a very small proportion of their quality And are much greater than the radius of the Earth, but the density is lower. Long terms, the distance between planets to the sun (a use that) a = 0.4 +0.3 * 2n-2 (an astronomical unit) n one that is far from near to the first planet-n (see the table) of the Earth, Mars, Jupiter, Saturn , Uranus, Neptunes rotation period to 12 hours a day or so, Mercury, Venuss rotation period is very long, were 58.65 days, 243 days and 6.387 day, most of the planets rotation and the direction of the revolution in the same direction, but Venus is the opposite. In addition to Mercury and Venus, other planets have Raozhuan satellite, the satellite system poses. In the solar system, has now found more than 1600 comets, most of the comet is in the same direction around the sun, but there are also reverse the revolution. Comet around the Sun in the operation of a strange shape change. In the solar system are a large number of small meteoroids, and some groups of the meteoroid is, the meteor is the product of the collapse of the comet. Large meteoroid landed on the ground to become meteorites. The solar system is an insignificant part of the galaxy, the Milky Way that it is only in the 100,000,000,000 stars in one of its center of the Milky Way from the 1000 second gap of about 8.5, or less than 30,000 light-years. With the sun throughout the solar system rotating around the center of the Milky Way. Can be s