Scientists from NASA and the Canadian Space Agency have been using Pavilion Lake as a testing ground for the future human exploration of other worlds. Pavilion Lake, in British Columbia, Canada, is home to a biological mystery. Microbialites, coral-like structures built by bacteria, in a variety of sizes and shapes, carpet the lakebed. That’s unusual for a freshwater lake like Pavilion. Exploration of Pavilion Lake is helping biologists understand this unique environment – and it’s also helping astronauts prepare for future human exploration of other worlds.