Cassini Crosses Saturn's Ring Plane
影像版權: NASA / JPL / SSI ; 動畫: Gordan Ugarkovic & Emily Lakdawalla
Explanation:
What would the rings of Saturn look like if you passed right through the ring plane? To find out, NASA aimed cameras from the Cassini spacecraft right at Saturn's rings as the robotic explorer passed from the sunlit side of the rings to the shadowed side. Resulting images from a vantage point outside the rings and most moons, but inside the orbit of Titan, have been gathered together in the above time-lapse movie. The dramatic movie demonstrates that ring particle density and reflectivity makes some parts of the shadowed side nearly the photographic negative of the sunlit side, but nearly empty regions remain continually dark. Visible also are Saturn-orbiting moons Enceladus, Mimas, Janus, Epimetheus, Prometheus, and Pandora. The extreme thinness of Saturn's rings can be appreciated from frames taken near the crossing time.
說明:
如果你從土星環面穿過，土星環看起來會是什麼樣子？為了證明這點，美國太空總署利用正在土星環旁的卡西尼號太空船，當探測船從環的向陽面走到背陽面的時候來觀察。拍攝的結果就是上面這張動畫，除了環之外，多數在泰坦軌道以內的衛星也都出現在影片中。由這精采的影片看得出，由於環上粒子的密度和反射率不同，有些地方在向陽面和背陽面看起來是完全反相的，但幾乎沒有東西的地區看起來則一直都是黑的。影片中可以看到幾顆土星的衛星，分別是土衛二(Enceladus)，土衛一(Mimas)，土衛十(Janus)，土衛十一(Epimetheus)，土衛十六(Prometheus)，以及土衛十七(Pandora)。此外，由卡西尼號正通過環面時的影像，可以知道土星環是非常薄的。
資料來源: Scientific American
Department of Physics, NCKU
