[thedoc (OP)]

America's National Aeronautics and Space Administration asks, "Has life evolved elsewhere in the solar system?" Indeed it has. In Question Answered (Amazon Kindle, 2012), I show, statistically, that microbes live in Europa, a moon of Jupiter. So we know where to find life beyond Earth...

Read the article then tell us what you think...

[Pmb]

I don't know where you got the idea that if something has a large probability of occuring then it occured but you're wrong. It's also a misuse of statistics to argue as such. Statistics only give you the chance that something occured based on certain postulates or theorems on which the statstical data is based. Either what was expected to occur didn't occur or there is a flaw in the postulates and/or theorems that they're based on.

I short - No. It is impossible to prove something exists based on statistics.

[evan_au]

The 122 life-filled seas quoted in the article do not prove that a 123rd sea on Europa must also be filled with life.
The 122 seas on Earth really just give 1 example: life on Earth. And you can't readily use just 1 example to extrapolate to all other possible examples.

There are barriers between the seas on Earth - but there are far more significant barriers between Earth, Europa & Ganymede:

• Heating & mechanical shock due to meteorite impacts
  
• Desiccation from the vacuum of space
  
• High radiation in space (although tests on the ISS have shown that some bacteria can survive long exposure)
  
• Potentially incredibly long journey time
  
• Extremely cold surface temperatures on these outer icy worlds
  
• Kilometers of ice before reaching liquid water deep inside
  
• Lack of sunlight on these outer worlds, which will not support photosynthesising algae
  

Regardless of your assumptions and calculated probabilities, the real test is to go and have a look - and there have been some concepts for such a space mission.

The recent investigations at Lake Vostok in Antarctica are a small-scale test of techniques which might be required to drill through many kilometers of ice on these planetary iceballs.

However, an easier target may be the Tiger Stripes on Enceladus, where water vapour is brought to the surface by internal pressures. A probe which sat on the surface could sample these cryogenic geysers to detect any organics being blasted into space.