November 28, 2010
We've found a place to send the Kardashians
Scientists have to be pretty pumped about this one.
The Cassini-Huygens spacecraft recently performed the closest flyby of Rhea, the second-largest moon of Saturn, ever, to discover what scientists have long suspected: Rhea, like a couple of Jupiter’s moons, has a little baby atmosphere. And while this atmosphere is mostly oxygen and carbon dioxide, there isn’t enough oxygen to be breathable by humans; and while the carbon dioxide could be cause by the existence of rudimentary life, there are a lot of other things that could cause it to appear.
In order to get a good reading, Cassini had to fly within 60 miles of Rhea’s surface (for comparison, 60 miles up on Earth, and you’ve just reached the beginning of the Thermosphere, higher than meteors but below the Space Shuttle, right about where the Aurora hangs out). It turns out that oxygen makes up about 70% of Rhea’s atmosphere, but it’s still about 5,000,000,000,000 times thinner than Earth’s atmosphere. So, not an opportunity for human explorers to breathe in an alien sky just yet.
So perhaps, just perhaps, unintelligent life lives on Rhea. I'm sure they'll get their own reality TV series.