It might sound crazy, but it is possible that some of the earliest components of life were carried to Earth on a meteorite. The five basic building blocks of DNA have been found in meteorites.

It isn't that the DNA was found on a rock from outer space. Each of the five basic compounds which make up DNA andRNA have been found in meteorite samples. The final two nucleobases have been found on meteorites.

Conceptual image of meteoroids delivering nucleobases to ancient Earth. The nucleobases are represented by structural diagrams with hydrogen atoms as white spheres, carbon as black, nitrogen as blue and oxygen as red.
Conceptual image of meteoroids delivering nucleobases to ancient Earth. The nucleobases are represented by structural diagrams with hydrogen atoms as white spheres, carbon as black, nitrogen as blue, and oxygen as red. NASA Goddard/CI Lab/Dan Gallagher

The complete set of nucleobases used in life today could have been available on Earth when life emerged, according to one of the authors.

The two outstanding nucleobases were cytosine and thymine. The other three nucleobases have a more delicate structure which is easy to break down by the process of collecting and analyzing samples. NASA describes the traditional method of analysis of these samples as making a meteorite tea, in which small samples from a meteorite are put into hot liquid so that the samples are extract and the watery solution can be studied.

The good stuff in the water extracts could have been key building blocks for the origin of life on Earth, according to Glavin.

The two remaining nucleobases required a more careful method to be identified, using cool water and a more sensitive analysis process.

It's still not certain whether the ingredients for life came to Earth on a meteorite. Life could have arisen from the interactions of organic compounds on a very young planet. Future research into the topic can be opened up by this research.

It is exciting to see the progress in the making of the fundamental molecule.

The journal Nature has published the research.

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