Mon 6 Feb 2006
How to use freely available images to make the planet of your dreams
A while back, I was called upon to terraform the planet Mars. Having a couple of free hours, I decided to take up the challenge, and turn the red planet blue.
I needed some striking space imagery for pitch material for a proposed space-based MMPO. I’ve spent a fair bit of time tromping around the NASA and USGS (US Geological Survey) websites, glorying at the bounty that our tax dollars make available on the net (see list of links at the end of the tutorial).
The Raw Materials
A cylindrical projection of the Mars surface, taken by one of the planetary surveys done by NASA.
It may seem trivial to be able sit down at your computer and pull up an image like this, but think for a moment at the work it has taken to send these probes, about the size of a Volkswagen Bug, hurtling into space, bouncing through the gravity wells of planet after planet, taking these images and beaming them back to us here on Earth, sometimes taking a decade or more to accomplish the mission. Truly one of the most awe inspiring of human accomplishments.
I’ve scaled down all the images I’ve used in the terraforming project, because I’m paying for bandwidth. The government has great big servers, so go pound on them if you want the full size images…};^) The image below is a sample of the detail you get on these maps. Depending on the use you have in mind, you may need to go through the map with the Photoshop Clone Tool or similar, depending on what software you use, and clean up some glitches and mosaic lines if you think they will show up in your final images. This image was clean enough for my use.
Next on the list was a topographic map (in the same cylindrical projection) of Mars. There are topo maps of Earth, Mars and Venus on the net. There may be a few others, mostly moons. The topographic maps for gas giants are none too interesting.
One of the things that jumps out at you looking at the Mars topo is that at some point in the past, Mars got the crap kicked out of it. In topo maps, white is high, and black is low. The big black spot is where something big hit the planet. But the upper dark band is worse, something enormous hit and pretty much melted half the planet. That’s why there is not much detail, craters, mountains, etc., on that side of Mars. In addition, the other hemisphere was pushed up dramatically. It’s almost like there’s a cliff that circles Mars, delineated by the white/black hemispheres.
Another point of interest is the white spot in the upper left quadrant. This is Olympus Mons, the tallest mountain in the solar system, and a volcano to boot! The mountain is about the size of the state of Arizona, and is about 16 miles (25 Km) high. Almost all the raw materials have been gathered.
All that remains is finding some cloud cover. Novice terraformers might be tempted to use a fractal pattern for cloud cover, but trust me, don’t. Another benefit of the space program; people know what clouds look like from space. There are some good Earth cloud plates floating around on the net, and NOAA (National Oceanic and Atmospheric Administration) takes pictures of Earth’s cloud cover 24/7. Dig around their server for useful images, or make your own.
The plate above is a nice mosaic, though it could be trouble in an animation, since a quick glance detects that it is a hemisphere’s worth of cloud cover cloned (and indeed, many smaller internal features are also cloned. Framed correctly, it is perfect for stills and limited animation.
Etc.
