charles 2009-3-27 11:04
木星火山衛星的硫黃煙柱
The Prometheus Plume
[img]http://i11.tinypic.com/2vjwfhw.jpg[/img]
影像提供: Galileo Project, JPL, NASA
[color=navy]Explanation: [/color]
[color=dimgray]What's happening on Jupiter's moon Io? Two sulfurous eruptions are visible on Jupiter's volcanic moon Io in this color composite image from the robotic Galileo spacecraft that orbited Jupiter from 1995 to 2003. At the image top, over Io's limb, a bluish plume rises about 140 kilometers above the surface of a volcanic caldera known as Pillan Patera. In the image middle, near the night/day shadow line, the ring shaped Prometheus plume is seen rising about 75 kilometers above Io while casting a shadow below the volcanic vent. Named for the Greek god who gave mortals fire, the Prometheus plume is visible in every image ever made of the region dating back to the Voyager flybys of 1979 - presenting the possibility that this plume has been continuously active for at least 18 years. The above digitally sharpened image was originally recorded in 1997 on June 28 from a distance of about 600,000 kilometers. [/color]
[color=navy]說明:[/color]
[color=dimgray]木衛一發生了什麼事? 無人伽利略號太空船在1995年到2003年之間探索木星，由它所拍攝照片組合出來的上面這幅影像，呈現了木星火山衛星-木衛一的兩道硫黃煙柱。 在影像頂端的木衛一臨邊上方的藍色煙柱，高聳出Pillan Patera的火山口約140公里。 在影像中央靠近日夜分界線附近，名為普洛米修斯的環狀煙柱突出在木衛一的表面上空，這道高度有75公里的煙柱，在火山口的右方投下一道長長的影子。 這道煙柱是以希臘神話中帶給人類火種的神祇普洛米修斯 (Prometheus)來命名。從1979年航行家探測船飛越回傳的影像起，普洛米修斯煙柱出現在這個區域所有的影像中，也因此科學家懷疑，這道煙柱噴發的期間至少已經超過18年了。 這張經過銳利化的影像拍攝於1997年的6月28日，當時航行家探測船距離木衛一大約有60萬公里。 [/color]
[size=2]資料來源: Scientific American
Department of Physics, NCKU[/size][color=white][size=1]
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