Letter from Thomas Gold to Professor Harold C Urey, University of California Apologises for not being able to come to a meeting. Thinks that Mars is a 'very unsuitable place for life' due to the 'very low atmospheric density on Mars (11 milibars) and all the other information that we now have'. Thinks that we should perhaps consider the possibility of there being life on Mars but deems it unlikely. 19 July 1965