Cassini Discovers Oxygen Around Saturn's Moon
NASA's Cassini Spacecraft, which has been orbiting Saturn for about six years, has not only sent back amazing pictures, but also, exciting discoveries about the ringed planet. Just a few months back, the spacecraft found evidence of alien life on Titan, Saturn's largest moon and now, it seems that Rhea, its second largest moon has an atmosphere similar to that of Earth.
Earlier this week, scientists revealed the Rhea's thin atmosphere comprised of carbon dioxide and oxygen. This is the first time a spacecraft has been able capture direct evidence of oxygen on a planet other than Earth. Previously the only evidence of oxygen has been gleaned from wisps detected by the Hubble Telescope.
The scientists believe that the oxygen in Rhea's atmosphere is derived from the ice off the surface of the frozen moon. As Saturn's magnetic field rotates around the moon it showers it with energetic particles. When these hit Rhea, they break the water molecules on its surface, releasing the oxygen. The carbon dioxide could be the result of carbon rich materials deposited by meteors that smash against the moon's surface or simply, the release of dry ice that is trapped inside.
While this is great news, the scientists also concluded that the atmosphere around Rhea's 1500 km circumference, is about 5 trillion times less dense than that of Earth and therefore, not enough to sustain life. However, what it does prove is that there could be other planets in our Universe or Solar System, with similar atmospheres, raising the probability of alien life.
This is probably not the last we hear about the fascinating finds on Saturn. The Cassini Solstice Mission is expected to continue until September 2017 and besides exploring Saturn's moons, it will also analyze its infamous rings, before the mission is completed - So stay tuned, for more fascinating news.
Sources: guardian.co.uk, redorbit.com