In the midst of all this hoopla about Deep Impact, I haven't been able to give the proper attention to Cassini, which began its second year of operations at Saturn today. I hope to pay homage to that next week. In celebration of the anniversary, the mission has made its first release of data to the Planetary Data System, or PDS. (The release was made with absolutely no fanfare -- I found this out from the Titan Today weblog.)
The PDS is the repository of all data for NASA missions. Once data is delivered by a mission to the PDS -- an event that happens at preplanned, regularly scheduled intervals -- the data are available to everyone, professional and armchair scientists alike. The data are in a PDS-specific format that is most useful to scientists with sophisticated data analysis tools, but the PDS makes some basic software available that you can use to view their data if you are persistent.
Or the images can actually be opened as "raw" format images in Photoshop, if you know the size of the image. Most Cassini images are 1048 pixels wide by 1028 high, with the image occupying the lower right 1024-by-1024 square corner.
If you visit that PDS website, you'll see you can download data for lots of missions -- Voyager, Viking, Mars Pathfinder, Mars Odyssey, Mars Global Surveyor, the Mars Exploration Rovers, Galileo, and Clementine. Go play with the data, if you've a mind to. If you're an American taxpayer, you paid for it; it's yours as much as anybody else's!