土卫八：一颗表面怪异的卫星。

Saturn's Iapetus: Moon with a Strange Surface
Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA
Explanation: What has happened to Saturn's moon Iapetus? A strange ridge crosses the moon near the equator, visible near the bottom of the above image, making Iapetus appear similar to the pit of a peach. Half of Iapetus is so dark that it can nearly disappear when viewed from Earth. Recent observations show that the degree of darkness of the terrain is strangely uniform, like a dark coating was somehow recently applied to an ancient and highly cratered surface. The other half of Iapetus is relatively bright but oddly covered with long and thin streaks of dark. A 400-kilometer wide impact basin is visible near the image center, delineated by deep scarps that drop sharply to the crater floor. The above image was taken by the Saturn-orbiting Cassini spacecraft during a flyby of Iapetus at the end of last year.

看起来好象是南北两个半球被焊在一起，焊工水平还比较一般 :mrgreen:

太空核桃，呵呵

挺吓人的  中间 那个环是怎么 造成的

[quote:11c718e1d6="zxycom"]看起来好象是南北两个半球被焊在一起，焊工水平还比较一般 :mrgreen:[/quote]

:wink: 形容得非常形象。

:shock:

好象被硫酸腐蚀过一样啊!
可怕,好象是铅制的 :roll:

说它像核桃（形状）也很贴切！

[quote:41d5d1e99c="光谱"]说它像核桃（形状）也很贴切！[/quote]

: 对的确像。 ^^

还真像一条焊缝 :shock:

[quote:8c1f790f27="崔巍"]挺吓人的  中间 那个环是怎么 造成的[/quote]中间那个是山脉吗？（如果是那就真的…… :shock: ）

真的像核桃是吧哈哈~~~

好大的一颗核桃啊 :shock:  :shock:  :shock:
刚刚还在考虑是先吃大核桃还是小核桃呢 :mrgreen:  :mrgreen:  :mrgreen:

呵呵，看样子这核桃质量不怎么样了

第一次看到这么清晰的土卫八。