NASA首次發現土星衛星中含有氧氣
Saturn's second-largest moon Rhea has a thin atmosphere filled with oxygen and carbon dioxide, scientists said today.
科學家今天聲稱，在土衛五--土星的第二大衛星—一層稀薄的大氣中含有氧氣和二氧化碳。
The discovery by Nasa’s Cassini-Huygens mission is the first time a spacecraft has captured direct evidence of an oxygen atmosphere on a world other than Earth.
美國宇航局“卡西尼-惠更斯”計劃的發現，是首次宇宙飛船獲得直接的證據證明在地球外的領域存在氧氣環境。
The presence of the moon’s exosphere was confirmed by instruments on the Cassini probe which orbits Saturn and its moons.
圍繞土星和它的衛星運行的卡西尼號探測器證實了衛星外逸層的存在。
The mission reveals that the atmosphere of Rhea, Saturn’s second largest moon at 1500 km wide, is extremely thin and is sustained by high energy particles bombarding its icy surface and kicking up atoms, molecules and ions into the atmosphere.
計劃顯示土衛五的大氣極其稀薄，並且一直被高能粒子轟擊其冰表面導致原子，分子和離子進入大氣。
The findings were published today in the journal Science.
這項研究結果發表在今日的《科學》雜誌上。
'The new results suggest that active, complex chemistry involving oxygen may be quite common throughout the solar system and even our universe,' said Dr Ben Teolis, the study’s lead auithor from the Southwest Research Institute in San Antonio.
這項研究的倡導者，美國聖安東尼奧西南研究所的Ben Teolis博士說：“新的研究結果表明，在整個太陽系，甚至宇宙中，包括氧氣在內的，活躍的，複雜化學構成其實很普遍。”
‘Such chemistry could be a pre-requisite for life. All evidence from Cassini indicates Rhea is too cold and devoid of the liquid water necessary for life as we know it.’
“這樣的化學構成可能是生命存在的先決條件。卡西尼計劃的所有證據都表明土衛五太過寒冷，並且缺乏生命必需的液態水。”
