To celebrate the 51st anniversary of Apollo 11’s historic moon landing, Google’s July 20, 2020, Doodle has recognized Turkish Astronomer Professor Dilhan Eryurt. Her research into stellar evolution, particularly of the Sun, helped prepare the mission’s astronauts for the lunar environment. For this work, she was awarded the 1969 Apollo Achievement Award.
Born in Izmir, Turkey, on November 29, 1926, Eryurt displayed an affinity for mathematics at a young age and went on to study the subject at Istanbul University. Taken by the stars, Eryurt continued her studies in astrophysics, and after graduation worked for two years, unpaid, as an honorary assistant. Undeterred, Eryurt helped to open Ankara University’s Astronomy Department and, following a brief stint at the University of Michigan, completed her doctorate back in Ankara in 1953.
After a few years as an associate professor of astronomy, Eryurt was awarded a scholarship with the International Atomic Energy Agency in Canada. Faced with a computer for the first time, Eryurt not only had to learn how to write computer programs but then use this newfound knowledge to investigate the internal structures of stars of different masses.
The next chapter of Eryurt’s life was in the United States. At Indiana University, Eryurt turned her attention to the evolution of stars, looking in particular at the transition from small to large mass stars. Then, in 1961, Eryurt became the first female Turkish scientist to work for NASA in the Goddard Institute for Space Studies, New York City. In collaboration with a previous colleague, Alastair G. W. Cameron, Eryurt took a deeper look into the Sun’s past.
At the time, astronomers believed that the Sun had brightened over the course of its life to reach the observed levels of the day. However, Eryurt realized that in fact the opposite was true – 4.5 billion years ago the Sun was a lot hotter and brighter, and had cooled to its present state. This led her to make further calculations of the release of neutrinos from the Sun, which are particles that carry solar energy through space. On location at the University of California, Eryurt also studied the formation and development of main-sequence stars (a star phase that our Sun is currently in).
Eryurt’s work on solar modeling provided Apollo 11 engineers and astronauts with crucial information of the Sun’s impact on the lunar landscape. In recognition of her achievements, Eryurt was awarded the Apollo Achievement Award in 1969. Concluding her work at NASA in 1973, Eryurt returned to Turkey to found the Department of Astrophysics in the Middle East Technical University (METU).
In the years that followed, Eryurt continued to share her love for the universe with others, whether it be through her organization of Turkey’s National Astronomy Congress or as the Dean of METU’s Faculty of Arts and Sciences. Having retired from METU in 1993, Eryurt lived for a further 19 years before passing away in 2012.
Professor Eryurt is another wonderful example of someone who reached for the stars despite the obstacles that lay in the way.