Abstract

In the Solar System, Mars is one of the most explored bodies and the most Earth-like planets. Life on Mars has been imagined in novels and movies, although the planet is granted wars or ominous omens in many ancient cultures. Since the first successful flyby in 1965, close-up scientific observations unveiled the mysterious surface of Mars to the public. Viking 1 and 2 achieved the first successful landing missions in 1976 and subsequently conducted the first biological experiments on Mars. This is where it all begins.

Decades of detections found that the Red Planet used to be covered by a global magnetic field, thick atmosphere, and likely vast water bodies. A number of rovers have additionally detected the emission of methane and the storage of organic matter in situ. These conditions are friendly to life as we know it. Thus, it remains inconclusive whether early Mars is possible to harbor life and whether signs of life can be recorded over geological time.

Previously, principles of “follow the water”, “follow the carbon”, “follow the nitrogen”, “follow the phosphorus”, or “follow the energy” have been the primary directions of exploration to detect habitable environments and life. However, these routes are insufficient to identify highly promising environments for the detection of life with regard to a complex and comprehensive habitable condition.

Through a series of examinations of serpentinization, we found that products of this process can indicate not only the presence of local water environments, but also of life-supporting elements, minerals, and energetic and chemical processes. In particular, mineral products of serpentinization can be preserved over millions or even billions of years for us to study. To detect biological activities in more habitable environments, chemical and isotopic traces of life can be evaluated using spectroscopic or mass spectrometric techniques. If with returned samples, in-laboratory higher-precision instruments will bring more groundbreaking findings.

This talk will primarily focus on introducing the magnificent journey of the search for habitable environments and life on Mars based on Mars exploration programs as well as Mars analog studies on Earth.