Earth. Wait… is it not a trick question?
How can someone possibly make a probability claim of 5% about the likelihood of finding life somewhere, even anywhere else -much less after narrowing it down to two moons? Aren’t you just totally making that number up and then using it as your justification to go look there?
Edit- It’s funny you say “I got my money on…” ‘cuz it would cost a LOT of everyone’s money to go look. Are there not better projects that would actually improve life on Earth than this?
I realize indirectly the space program has done a lot for us, but then I’d say you’d have to use that as a rational justification.
Personally I don’t care if there’s alien bacteria out there. Let’s cure cancer. Let’s fix our genomes so we stay healthy. Let’s put a colony on Mars if you need a better space-based goal.