Letter from Thomas Gold to Dr Gordon Pettengill, Massachusetts Institute of Technology, Lincoln Laboratory, Lexington, Massachusetts Thanks Dr Pettengill for sending him 'the magnificent Haystack lunar maps'. Suggests that they should arrange a meeting at Lincoln Laboratory soon to talk about 'whatever joint evaluation of the lunar data' may be required. Says that he wants to see the 'intensity plots through craters such as Tycho' compared as there is an indication that 'both the center and the far exterior are rougher at the longer wavelength'. Goes onto discuss this in further detail. 8 March 1967