Carbon is a key component of all known life on Earth, representing about 45-50% of all dry biomass. Carbon is abundant on Earth. It is also lightweight and relatively small in size, that make it easier for enzymes to manipulate carbon molecules. It is frequently assumed in astrobiology that if life exists elsewhere in the universe, it will also be carbon-based. In fact, research has been ongoing since the 1960’s, to determine what the proportion of C-14 in the atmosphere and what amount has been for the past 50,000 years.