mariah 2009-3-24 14:33
擁擠的太陽系
Our Busy Solar System
[img]http://i15.tinypic.com/34rhopc.gif[/img]
影像版權與提供: MPC, CBAT, Harvard CfA, IAU
[color=navy]Explanation: [/color]
[color=dimgray]Our Solar System is a busy place. Although the major planets get the most press, a swarm of rocks, comets, and asteroids also exist. The above plot shows the placement of known inner Solar System objects on 2002 July 20. The light blue lines indicate the orbits of planets. The green dots indicate asteroids, officially known as minor planets. The red dots indicate asteroids that come within 1.3 Earth-Sun distances (AU) of the Sun and so pose an increased (although small) collision risk with the Earth. Comets appear as dark blue squares, while dark blue points are Jupiter Trojans, asteroids that orbit just ahead of, or just behind Jupiter. Note that most asteroids of the inner Solar System orbit between Mars and Jupiter in the main asteroid belt. Every day this plot shifts with objects nearer the Sun typically shifting the most. The current locations of these objects can be found here. [/color]
[color=navy]說明:[/color]
[color=dimgray]我們的太陽系是個擁擠的地方。雖然大行星吸引了大部份的目光，但另有一大群石頭、彗星和小行星存在則是不爭的事實。上面這張圖片呈現了到 2002年7月20日為止，已知的內太陽系天體之位置。淡藍色線是行星的軌道，綠色點為小行星。紅點標示會運行到離太陽1.3個太陽-地球距離(AU，或稱天文單位)內的小行星，它們和地球相撞的危險會高一些。彗星則是淡藍色的方塊，而暗藍色點則是木星的特洛伊群小行星，它們在木星的前方和後方伴隨木星公轉。大部份內太陽系內小行星的軌道，在火星和木星之間的主小行星帶。每一天，這幅分佈圖都會隨天體繞行太陽而改變，靠太陽愈近者移動愈多，這些天體現行的位置請看這裡。[/color]
[size=2]資料來源: Scientific American
Department of Physics, NCKU[/size][color=white][size=1]
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