Celestia Forums

Sorry- it has been a while... Yes, the "lapse rate" thing is -dT/dz, as you mentioned. I'm sure it is hidden in the other formula I posted. And, yes, I looked all this stuff up on Wikipedia. :roll: This is definitely out of my field, but I have a science background, so I understand how app...

Whatever the "lapse" rate is supposed to mean, the temperature dependence of the exponent is a crucial effect and all but small! The lapse rate is the change in temperature with a given change in altitude. On Earth I think it averages 6.5C/1000m or so, but it is really variable depending ...

>> The most important one being the temperature dependence of the coefficient in front of the altitude in the exponent. In order to get a reasonable prediction, one has to assume a "standard atmosphere" where the temperature decreases by a certain amount per n meters of altitude. Yes, I th...

Don, Well, I just found a formula to very roughly estimate atmospheric pressure at a given altitude given a pressure at "sea level" and local gravity. P = Po * exp (-g * h / H) wherein P = pressure in atmospheres Po = pressure in atmospheres at "sea level" g = gravity in Earth G ...

Don, Wow. Well, my prejudices are easy enough to predict- I like the drier Mars. In particular the high, cold desert of Terra Sabaea warms my heart. Also, having Terra Cimmeria and Terra Sirenum as high, cold deserts with verdant valleys in the low areas is rather aesthetically pleasing, too. I supp...

Don, Wow. You motivated me to figure out how to load new textures. That whole "change the ssc file" thing threw me for a few minutes, and I don't think that I have the normal map working properly (Olympus Mons still looks flat, for instance), but I'm still very impressed. It's beautiful, D...

Don, As I've said-it's your world, Brother. Do as you like. I'm just trying to learn here, for the sake of my own thought-experiment. I understand why a thick atmosphere is desirable, as far as warming and radiation shielding, really I do. I guess that what I didn't understand was that you are tryin...

Don, Thanks for the information on the south polar depression... I'll buy that. Actually, shortly after my last post I had wondered if the south polar contour lines that I was seeing represented the surface of the ice sheet rather than ground level. So I guess they do. Hmm. Even so, I think the pole...

Don, By all means, please, let me know about that south polar depression. As fate would have it I had been erroneously looking at the NORTH pole when I saw that depression at 330 E. Looking at the south pole I see no depression whatsoever. As I mentioned I'm using pdfs of those USGS topo maps that y...

Don, I understand the whole "cut out the tropics" model- as a matter of fact I think that you mentioned it in a previous post. I also know that it leaves some details out, such as the fact that seasons would not be as dramatic at Mars' equator as they are in Maryland, etc. Though, Mars' or...

fsgregs, Please, call me Dean. "Acrosome" is just a login name I have been using since college, when we were discouraged from using our real names for some reason. I had actually already found the CelestiaMotherLode by trolling this forum, including the educational activities. But, honestl...

Don, Howdy, I'm new here. I found this forum (and Celestia) a couple of days ago after intensive google searching for Mas terraformation schemes. I have to say- beautiful work. You cannot get enough praise for it. My package manager loaded Celestia without a hitch (I run Ubuntu Linux) and I'm still ...