WHERE DO WE START LOOKING FOR LIFE??
Bacteria on Earth have been found in a variety of environments from warm, well-oxygenated areas to cold, anaerobic environments. In order to find bacteria or bacteria fossils on Mars, we start looking in similar environments in which they are found on Earth. These environments are correlated from what we know about the Martian environment and what we have inferred about the ancient Martian atmosphere/environment.