Biology 11th Edition by Cecie Starr ,Ralph Taggart

تمرين 3

Mars formed about 5 million years earlier than Earth, and it has a similar composition but is far richer in iron. It is farther from the sun and much chillier, with an average surface temperature of 63° C. Today, nearly all of the water on Mars is permanently frozen in soil. To some researchers, photographs of certain geological features indicate that liquid water might have flowed across the planets surface during an earlier and warmer time. The Martian atmophere is now richer in carbon dioxide than Earths, but very low in nitrogen and oxygen. Based on this information, would you rule out the possibility that life could have existed on Mars or that simple life forms could currently exist there Explain your reasoning.