它扁平的形状意味着土卫八曾经旋转得非常快，完成一次自转需要16个小时。
Its flattened shape implies that Iapetus once spun very quickly, completing a rotation in 16 hours.
科学家们认为光环外侧的物质向内移动并猛烈撞击“土卫八”。
Scientists think material from the outer ring moves inward and slams into Iapetus.
甚至只是对于土星的卫星土卫八粗略地一瞥，也足以表露出它的古怪。
EVEN a cursory glance at Saturn's moon Iapetus reveals it to be an oddball.
应用推荐