A recently published study in the Proceedings of the National Academy of Sciences of the United States of America indicates that the essential building blocks for early life on Earth may have indeed been delivered through extraterrestrial material such as meteorites. These molecules, known as nucleobases, are key components of DNA and have been found in meteorites several times before.
However, until now, scientists could never be certain that these compounds were native to the meteorites or if they were simply contamination from the terrestrial environment in which they landed. To this end, researchers analyzed eleven different organic-rich meteorites, called carbonaceous chondrites, for the presence of nucleobases and found that three of these molecules are very rare on Earth.
Additionally, none of these nucleobases were found in the soil or ice in close proximity to where the meteorites were found. This led the researchers to conclude that it was likely that these molecules were extraterrestrial in origin which could mean that life on Earth may have originally been seeded by such material