Following the war, Gascoigne and astronomer Gerald Kron used newly modernised telescopes at Mount Stromlo to determine that the distance between our galaxy and the Magellanic Cloud dwarf galaxies had been underestimated by a factor of two. Because this measurement was used to calibrate other distances in astronomy, the result effectively doubled the estimated size of the universe. They also found that star formation in the Magellanic Clouds had occurred more recently than in the Milky Way; this overturned the prevailing view that both had evolved in parallel. A major figure at Mount Stromlo Observatory, Gascoigne helped it develop from a solar observatory to a centre of stellar and galactic research, and was instrumental in the creation of its field observatory in northern New South Wales, Siding Spring Observatory. When the British and Australian governments agreed to jointly build the Anglo-Australian Telescope at Siding Spring, Gascoigne was involved from its initial conception and throughout its lengthy commissioning, taking its first photograph. Gascoigne was made an Officer of the Order of Australia for his contributions to astronomy and to the Anglo-Australian Telescope.