Science Education Standards:

Short Description: PP. 43-49. Groups analyze temperature and pressure graphs from the first 30 days of the Pathfinder mission and discuss whether liquid water could have existed once under these conditions. The pressures make water theoretically possible although the temperatures are below water's freezing point. Next, students look at images of Mars. By interpreting the landforms and comparing a river-cut valley on Mars with the Earth's Grand Canyon, they identify water as the agent that shaped the surface. They hypothesize about how water could have flowed across the Martian surface, even though current conditions make it virtually impossible for liquid water to exist. Finally, they consider how the considerable amount of water that seems to have flowed across the Martian surface could have disappeared. Note: This is a 105 page PDF.