Asteroid Bennu Contains Many Biochemical Building Blocks

[exchemist]

I saw a BBC report on this and looked up the paper in Nature Astronomy. It was published today: https://www.nature.com/articles/s41550-024-02472-9

It seems samples contain not only 14 out of the 21 amino acids (though racemic rather than showing a chiral preference), but also all 5 of the nucleobases found in RNA and DNA. So a lot of nitrogen-rich molecules. The authors suggest this points to reactions occurring in a low temperature regime, possibly one in which ammonia ice was stable, e.g. in the protoplanetary disc from which the planets and asteroids condensed.

This supports the hypothesis that many components for life could have arrived from meteorites, rather than necessarily having been formed ab initio on the Earth.  

 

Edited January 29 by exchemist

[Ken Fabian]

Yes, it does appear like abiogenesis got a head start with a wide range of precursor chemicals. Meteorite impact sites, perhaps in shallow water, where such materials would be concentrated could be significant to abiogenesis chemistry. Enough meteorites over enough time (and Earth has had both) means some will impact near hydrothermal vents and other places with "rare and unusual" conditions - over a whole planet and given hundreds of millions of years, not so much rare and unusual as extremely likely.