Question: is Jupiter made of rocks or liquid water?

Richard Moss answered on 4 Mar 2016:

It is called a “gas planet” as mostly it is made of gas. But it is so huge that its own gravity pushes the gas in the centre to be liquid. No space probes survive very long when we send them to Jupiter due to the large pressures. Like a submarine which goes very deep in the ocean.
It could be there is a rock in the very centre. Maybe you can take the challenge to build a space probe able to find out.