Letter from Thomas Gold to Dr Robert R Gilruth, Director, National Aeronautics and Space Administration [NASA], Manned Spacecraft Center, Houston, Texas Enclosing some notices about a Research Conference [not included with this letter] they are going to hold to consider small particle phenomena and the relation to lunar investigations and operations. Tells Dr Gilruth about the proposed conference and asks him if he would like to invite a couple of people to it. [1967]