Double Stars and the Return to Planetary Studies (1956–1973)

The modifications of Paul Muller in the 1950s and 1960s to make the Grande Lunette more suited to double star work are detailed. The renovated instrument was also used by Dollfus and Focas for high resolution planetary work, in support of NASA’s Mariner Mars missions. The method of double image micrometry yielded excellent measurements of the diameters of both major and minor planets.