National Geographic reports that DNA precursors were found in a 4.5-billion year old meteorite. When scientists dissolved parts of a asteroid fragment, they found uracil and xanthine. You might remember uracil as the “U” that pairs with the “A” in RNA (in DNA, “U” is replaced by “T”, thymine). Xanthine is produced when guanine (another RNA and DNA nucleic acid) degrades, and is a precursor to uric acid. So alien molecules may be not only in your cells, but IN YOUR PEE.
As Carl Sagan far more eloquently said:
We are star stuff which has taken its destiny into its own hands. The loom of time and space works the most astonishing transformations of matter.