NASA scientists have brought back from Mars a molecule they think is similar to DNA. Just like DNA, it is transcribed into a mRNA-like molecule. Unlike mRNA on Earth, though, it appears to use only three bases (A, C and T). Assuming that proteins were still made from this mRNA molecule and it was thought that 30 Amino Acids existed for this organism, what is the minimum number of bases likely to be in a codon? Explain your answer.