Is there life on Mars?(12)

The jackpot of this treasure hunt would be to find things like sugars, phospholipids (constituents of the membranes of cells), nucleotides (the “letters” of genetic material) or amino acids (the building blocks of proteins) that are characteristic of life on Earth. But consolation prizes might be available in the form of less direct signals of biology within the chemistry—traces of the actions of enzymes, for example. As Dr Vago observes, the way fatty acids are synthesised biologically on Earth means that they usually have an even number of carbon atoms, although there is nothing in their underlying chemistry which favours that in abiotic syntheses. Finding a pattern like this, or something equally chemically striking, in Martian organic molecules would be encouraging to those who hope that Mars has or once had life.