Air and Space: Life May Have Been More Likely to Originate on Mars Than on Earth

By Dirk Schulze-Makuch

    One question in astrobiology is whether life is likely to have arisen on Mars. A team of researchers led by Benton Clark from the Space Science Institute recently explored the question. They concluded that it was just as probable for life to have arisen on Mars as on Earth.

    There are four reasons for this conclusion. First, Mars probably received a lot more organic materials from asteroids and comets. Second, sulfur, an important biological element, is more common on Mars. Third, Mars had a head start in the biological process because the Earth was hit by a meteor between 20 to 100 million years after its creation, obliterating any biology. Finally, Mars experiences a lot of wet-dry and freeze-thaw cycles, which concentrates elements. These cycles, when exposed to air, would support the hydrothermal pond theory of life's origin. However, because only around 5% of Mars was covered by water, a deep ocean origin would make it unlikely for life to have started on Mars. Ultimately, the true origin of life on Earth has a lot of implications for the results of this study and the possibility of life on Mars.