Development of astrophysics, astronomy and cosmochemistry in the last two decade has widely provided a certain realistic perception of existence of extraterrestrial life in the Universe and even in our solar system. Progressive synthetic biology has also enabled us substantially to testify possible materials, configurations and evolutions of living systems, which are truly existing, or realistically and theoretically existable in the Earth or even in the elsewhere. These disciplines have opened a new era of universal biology, called as astrobiology, and the integrated knowledge and perspective has been renewing how to tackle one of the most fundamental questions in science, origin of life (OOL). Before the emergence of integrated astrobiology, the crucial goal in multiple disciplines of OOL studies was to give satisfactory solutions to the question: when, where and how our first ancestral life was generated in the early Earth. To this end, roughly speaking, one succeeded event, even if it is a miracle crystal of many low-probability processes but is logically consistent, may become a true answer. In the current astrobiological context, however, one possible episode for origin of earthly life is no more satisfactory scientific solution to substantial OOL. The likelihood of occurrence and connection though the OOL processes in the case of Earth should be justified by theoretical, mathematical and experimental methods, and the rarity or ubiquity of the whole and/or partial processes of earthly life under the conditions of possible extraterrestrial environments should be addressed in terms of the integrated astrobiological context. Here, for stepping into the next stage of OOL research, I briefly overview the several significant issues and disputing points raised through the outstanding works so far. I hope that this overview would shed light on our present standpoints to challenge OOL from astrobiological aspects in future.
Recent findings on Mars, the discovery of organic molecules, methane and reduced sulfur compounds that could be potential energy sources for microbes, possible liquid water flows on recurring slope lineae (RSL) and so on suggested that life might exist near the surface at present. Although life search experiments carried out by the Viking missions in 1970’s failed to detect life in Martian soil, more sensitive instruments have been developed, especially a fluorescence microscope would be a powerful tool to detect and visualize organic compounds surround by membranes and possessing metabolic activities, which are considered to be living cells.