From Chris Bury:

Re: Mars salt might have thwarted life (Feb. 15): I am not a scientist but an avid reader of anything extra terrestrial. This argument in the article:

“Not all wa­ter is fit to drink,” said An­drew Knoll, a Har­vard Uni­ver­s­ity bi­olo­g­ist who is on the sci­ence team for the NASA Mars rov­er Op­por­tun­ity. High con­centra­t­ions of dis­solved min­er­als as well as ac­ids may have thwar­t­ed mi­crobes from de­vel­op­ing on the red plan­et, he added.

is not actually valid as we all know microbes have been found live in very high concentrations of acids, alkalis and salts. And the salinity of the water which was there thousands or millions of years ago been observed and analysed by a remote body today is far fetched, and unbelievable.