Complex sentence: Andrew David Thackeray, an astronomer trained at Cambridge University, was director of the Radcliffe Observatory in Pretoria from 1951 to his retirement in 1974, and the discoverer Thackeray A.D., MNRAS 110,529,1950 of Thackeray's Globules in 1950.
Split into simpler sentences: Andrew David Thackeray, an astronomer trained at Cambridge University. He was then director of the Radcliffe Observatory in Pretoria from 1951 to his retirement in 1974, and the discoverer Thackeray A.D., MNRAS 110,529,1950 of Thackeray's Globules in 1950.