Could the compounds formed in the interstellar medium have reached Primitive Earth during formation or meteorological bombardment and have a decisive role in the production of prebiotic molecules? What compounds are formed in MIS, what is their resistance to temperature increase, photolysis, pressure increase? Are comets the vectors of complex molecules in sufficient quantities to have a role in prebiotic chemistry. What happens to these molecules on other bodies such as planets and satellites in the solar system. Why does the surface of Mars contain so few organic species? Is the role of liquid water from a "prebiotic pre-material" decisive?