Scientists have for the first time discovered an oxygen atmosphere on another world other than Earth.
While orbiting Saturn’s moon Rhea, Cassini spacecraft found evidence of a tenuous atmosphere infused with oxygen and carbon dioxide. This kind of chemistry could be a requirement for life….
Rhea is the second largest moon of Saturn. The heaviest cratered moon in our Solar System has a diameter of 1,528 kilometers (949 miles) it is less than a third the size of Saturn’s largest moon.
Rhea is tidally locked in phase with its parent. One side always faces toward Saturn.
Rhea’s surface temperatures are also similar to Dione and Tethys, being roughly as warm as -174°C (-281°F) in sunlit areas and ranging down to -220 degrees°C (-364°F) in shaded areas.
The density of oxygen detected on Rhea is probably about 5 trillion times less dense than in Earth’s atmosphere.
However, the formation of oxygen and carbon dioxide could possibly drive complex chemistry on the surfaces of many icy bodies in the universe.
“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, a Cassini team scientist based at Southwest Research Institute in San Antonio and lead author.
“Such chemistry could be a prerequisite for life. All evidence from Cassini indicates Rhea is too cold and devoid of the liquid water necessary for life as we know it.”
“Rhea’s oxygen appears to come from water ice on Rhea’s surface when Saturn’s magnetic field rotates over the moon and showers it with energetic particles trapped in the magnetic field,” said Professor Coates from the UCL Mullard Space Science Laboratory.