What were the major findings of the NASAs Phoenix Mars Lander?
All I know so far is the Phoenix Mars Lander found, mostly, those three things. The mission of Phoenix is to characterize the climate and geology of Mars and to prepare for human exploration. Therefore, most of the findings made by Phoenix is geographic aspects of Mars, so I guess that would be another “major” finding of Mars. In the sources, I’ve included a link to NASA’s Phoenix page. They have the latest news and images on Phoenix, which you might find of interest.