Saturn's second-largest moon Rhea has a thin atmosphere filled with oxygen and carbon dioxide, scientists said today. 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. The presence of the moon’s exosphere was confirmed by instruments on the Cassini probe which orbits Saturn and its moons. 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. The findings were published today in the journal Science. The density of oxygen is about 5 trillion times less dense than in Earth’s atmosphere. '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. ‘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.’ Dr Geraint Jones, from the UCL Mullard Space Science Laboratory, said:'The discovery of this tenuous atmosphere provides key information on how radiation can drive chemistry on icy surfaces throughout the universe.' (Daily Mail)Friday, 26 November 2010
Oxygen found on Saturn moon: Nasa spacecraft discovers Rhea has thin atmosphere rich in O2
Saturn's second-largest moon Rhea has a thin atmosphere filled with oxygen and carbon dioxide, scientists said today. 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. The presence of the moon’s exosphere was confirmed by instruments on the Cassini probe which orbits Saturn and its moons. 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. The findings were published today in the journal Science. The density of oxygen is about 5 trillion times less dense than in Earth’s atmosphere. '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. ‘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.’ Dr Geraint Jones, from the UCL Mullard Space Science Laboratory, said:'The discovery of this tenuous atmosphere provides key information on how radiation can drive chemistry on icy surfaces throughout the universe.' (Daily Mail)