0

Meteorites could have brought 5 DNA genetic ‘letters’ to Earth

Key DNA building blocks that previous research mysteriously failed to discover in meteorites have now been discovered in space rocks, suggesting that cosmic impacts could have helped deliver these vital ingredients of life to ancient Earth.

DNA is made up of four main building blocks: nucleobases called adenine (A), thymine (T), cytosine (C), and guanine (G). DNA’s sister molecule, RNA, also uses A, C, and G, but swaps thymine for uracil (U). Scientists wonder if meteorites could have helped deliver these compounds to land have previously looked for nucleobases in space rocks, but until now, scientists had only detected A and G in space rocks, and not T, C, or U.