The Terragen thing
About that whole DEM data into Terragen thing, can we forget that I ever thought of it? It's turned out to be an incredible challenge with few resources available to offer much help.
Taking a small break from the above, I've started to work with a sound designer (Alan Moffat) which I've not really done on any other project. Part of the inspiration for the audio has come from the discovery of the beautiful and haunting sounds of the planets and moons of our solar system recorded by two automated NASA probes, Voyager I and II. Picking up the audible vibration frequency of for instance, waves from the magnetospheres, trapped radio waves bouncing between the planets, the electromagnetic field noise in space itself, etc, these waves were then translated into sound waves, arranged and released on a five-volume collection of space music entitled "Symphonies of the Planets". Check out the amazing sounds of Jupiter below:
Sadly, no sounds of Mars have ever been recorded, despite efforts from the Planetary Society to do just that. In an email exchange I just had with them, they reported that "No sounds of Mars have ever been captured. We at the Planetary Society have tried. We flew the Mars Microphone on the failed NASA Mars Polar Lander mission. We have also attempted to get microphones on various other missions and partnered with others." So, with no sound files from Mars to reference, my sound designer and I are left to speculate, using NASA's recordings as a 'launch pad' (yeah, sorry - blame Alan for that one) and imagining what an alien dust storm might sound like within a future Martian landscape littered with the debris and partially functioning equipment of countless missions to the planet.