Definition and test for lifeName:Institution:Date: There is no universally accepted definition of living and life, but most definitions incorporate the shared characteristics of living things. Thus, the study of life has mostly focused on living organisms on planet earth. With the continued growth in technological know-how in spacecraft manufacture and outersapce exploration, the debate has been reignited once again. To gain a better understanding of what constitutes life, many scientists have integrated biological explanations with astronomy in expanding the functioning and composition of living tissues (Bortz, 2008). Up to now there is no widely accepted definition of life, but identifying similar characteristics in living things can help to create tests that detect presence of life.Adopting any of the various definitions would be inadequate as none of the explanations are robust enough. NASA conceptualized life as being both self sustaining and adhering to Darwinian explanations for evolution (Benner, 2010). Though widely accepted this definition ignores the fact that living things do not exist through a self sustaining system. Other widely accepted definitions point out that life occurs through reproduction (Popa, 2004), but this definition is also narrow as reproduction ceases at certain stages while life continues. The debate as to what really constitutes life is not irrelevant as space missions need to identify what constitutes life in their explorations. Furthermore, a precise definition is vital to understand the survival and living habits of other living things beyond the earth. There is also a need to identify the factors that make life hospitable for organisms in many habitats. Distinguishing between living and nonliving things is the first step before a universally accepted definition can take place. In the field of biology there are no agreeable criteria on what constitutes living things though biology is the study of life (Mullen, 2002). Another potential problem of defining and designing tests for life is that living things may share characteristics with non living things, for instance metabolism is common in organisms but may also be exhibited by non living organisms. A study conducted on Mars found out that injecting the Martian soil with radioactive ingredients later led to emission of carbon dioxide (Mullen, 2002) & (Nolan, 2008). Nonetheless, the study was inconclusive as the soil had unique composition that imitated metabolic reactions (Mullen, 2002). Origin and conceptualization of lifeAn understanding of the origin of life is crucial in designing tests that distinguish between life and non life forms. Historically, the earliest explanations of life looked into synthesization of amino acids as a possible explanation of life`s origin (Aubrey, 2008) & Weber (2010). However, the definition of life also depends on the purported origin, and hence the two cannot be separated from each other. In addition, these studies presu...