"Well, only about a fifth of the atmosphere being breathable works well enough for humans, so there's room for variation in here, even if I haven't looked into what the exact mix we're looking at is..."

He pauses to take a bite of that fruit, tapping the rind with one finger thoughtfully as he looks around.

"I've hardly gotten to reading up on the biology I've missed out on. Started with the engineering and..." Headshake. "There's so much it's hard to decide what order to take it all in."