The sites we used were used were www.google.com, Nasa, Youtube, Sketch Up (program), WALL-E (movie) http://marsmissionpbl.weebly.com http://www.mars-one.com http://www.universetoday.com/22603/mars-compared-to-earth/ http://myhub.pixorial.com/library#/library/content http://www.weebly.com http://www.exploratorium.edu/ronh/weight/ http://www.earthworksrecycling.com/prices/metalsellingprices.html