[rosbrith]

> So, is there an advanced hidden civilization underneath that gas and pressure?

A major plotline in "The Algebraist" by Iain M Banks (sci-fi, but not a Culture novel) centres around a species who live in gas giants.

> I wonder why they mention the price of the probe on there.

Some Guardian commenters like to express the opinion that space exploration is a waste of money which could be better spent on other projects closer to home, so I suspect there was an element of provocation to this.