Saturn's second-largest moon Rhea has a thin atmosphere filled with oxygen and carbon dioxide, scientists said today。
科学家今天声称，在土卫五--土星的第二大卫星—一层稀薄的大气中含有氧气和二氧化碳。
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。
美国宇航局“卡西尼-惠更斯”计划的发现，是首次宇宙飞船获得直接的证据证明在地球外的领域存在氧气环境。
The presence of the moon’s exosphere was confirmed by instruments on the Cassini probe which orbits Saturn and its moons。
围绕土星和它的卫星运行的卡西尼号探测器证实了卫星外逸层的存在。
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。
计划显示土卫五的大气极其稀薄，并且一直被高能粒子轰击其冰表面导致原子，分子和离子进入大气。
The findings were published today in the journal Science。
这项研究结果发表在今日的《科学》杂志上。
'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。
这项研究的倡导者，美国圣安东尼奥西南研究所的Ben Teolis博士说：“新的研究结果表明，在整个太阳系，甚至宇宙中，包括氧气在内的，活跃的，复杂化学构成其实很普遍。”
‘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.’
“这样的化学构成可能是生命存在的先决条件。卡西尼计划的所有证据都表明土卫五太过寒冷，并且缺乏生命必需的液态水。”
