The scale is truly enormous and may not be realistically achieved with the tools at hand (certainly not from me and my skill set with T2 at this point!). I have yet to see any illustrations, digital or illustrated that come close to being able to convey the full magnitude; as I said this is my 'approximation'. According to the book, the impacted landscape is 'millions of square miles of desolation' and a 'lunar-like' vista. In large part because of the disruption of the programmed (by the Ringworld Engineers)weather patterns, the area around the F.O.G. is arid with no appreciable precipitation. I truly would have loved to add some lakes, rivers, and vegetative areas to gain some scale, but that would not have been true to the original concept. As to how wide the diameter of the exit point is, who knows? Remember the 'moon' was vaporized at initial contact and forced itself thru the incredibly dense Ringworld base material ('Scrith' whose tensile properties have been an ongoing discussion in Physics and Engineering circles for some time now). The elevation of the artifact is about a 1,000 miles (whoa!), and the object is described as roughly 'conical', so what would the circumference of the base be? I'd attempt to stick it on a planetary surface to scale it up, but to defeat the curvature I'd have to have a planet with a radius that would extend a flat horizon for almost 1,000,000 miles (double-whoa!!), as the distance from rim wall to rim wall across the Ringworld floor is 997,000 miles (and 'flat', with the 'curvature' extending along the Ring inner surface for almost 600 million miles! Appearing to the human eye as 'flat' - the Ring being viewed as a gigantic 'arc' over the world) . A flat plain with that dimension might work, but is such an object (F.O.G.) even doable in T2, or any current software? As to the clouds: I'm hoping that the FrankB magic in the upcoming webinars might help me get a better grasp of that! If any one wants to have a go at this, I'll give you what I've started. At this point I'm undecided whether to continue the project or not.