The search for life on mars

Abstract

Though Mars is a cold and dry planet now, Mars would have harbored a large amount of liquid water on the surface early in its history. Mars could have been similar to the early Earth from which life arose 4 billion years ago, and life may have also emerged on Mars during this period. Although the Viking mission in 1976, which explored life on Mars, did not find evidence for life, many findings associated with the possibility of life have been discovered since the Viking mission: past and present aqueous environments, organic compounds, methane, reduced compounds suitable for microorganism energy sources, and so on. These findings suggest that life might exist on Mars. Habitable environments may be deep subsurface, but it may also be on or near the surface where physical and chemical conditions on which even terrestrial microorganisms to survive are found. Life detection instruments have been developed since the Viking mission. Traces or existence of Martian life might be found by future exploration.