In most of the planets, the composition of gases is nearly same, which includes hydrogen, helium, carbon, and oxygen. This clearly indicates the formation of similar type of biological molecules like carbohydrates, proteins, and nucleic acids. If the biological molecules are same, then the genetic code can also be same. This is because the genetic code is based on nucleotides. The similarity of nucleotides in outer space may be helpful to use the same genetic code for protein synthesis.
NASA (National Aeronautics and Space Administration) scientists tried to reproduce the building blocks of life in laboratory with outer space environment. This experiment resulted in formation of nitrogen bases like uracil, cytosine, and thymine. This laid the foundation that same genetic code can be used for protein synthesis in the outer space.