Conversation:

First - how come there are no other posts here - is Neptune that uninteresting? It's such a nice blue ball, and Triton is such an unusual satellite.

Secondly - how was the value of 560 m/s for the speed of sound arrived at? Given the planet's atmosphere and temperature shouldn't it be much lower?

I have no idea about the answer to your question, but I had to post because I , too thought it sad that no one has talked about poor Neptune for so many years.

So let's cheer the place up! Wrap up well- I hear there's high winds -and have a to keep yerself nice and cozy.

Neptune and Uranus actually come under the term of 'Ice Giants' and their upper atmospheres consist of ice particles. Also, a internal heat source is something of an incorrect term as only stars in some form or another produce their own heat. Heat generated by planets are a by-product of contraction and to a lesser extent radioactive decay.

As distant as the bodies are, the Sun's heat still does play a part in weather on these worlds. Even 5% of the sunlight recieved by the earth is still significant.