Interesting, so it looks at polymerisation of tartaric acid (TA, or O=C(O)C(O)C(O)C(=O)O in SMILES notation):

> They discovered that calcium dramatically alters how TA molecules link together. Without calcium, pure left- or right-handed TA readily polymerises into polyesters, but mixtures containing equal amounts of both forms fail to form polymers readily. However, in the presence of calcium, this pattern reverses -- calcium slows down the polymerisation of pure TA while enabling mixed solutions to polymerise.

Not so sure about their suggestion that poly-TA might be some kind of RNA or DNA precursor.

Interestingly in many astrobiology threads quite a lot of commenters use the racemic nature of organics on bolides as some trump card against the possibility of panspermia on earth. In this article we see that distinction is instead meaningless and merely salt conditions are sufficient to influence chirality in molecule formation from a homochiral or racemic state.

This is really interesting. If we’re the same chirality then we can eat aliens and maybe get some nutrients but probably not because they won’t have the same amino acids.