John A. O'Keefe (astronomer)

John Aloysius O'Keefe III (October 13, 1916 – September 8, 2000) was an expert in planetary science and astrogeology with the National Aeronautics and Space Administration (NASA) from 1958 to 1995.

He and his co-authors, Ann Eckels and Ken Squires, are credited with the discovery that the Earth had a significant third degree zonal spherical harmonic in its gravitational field using U.S. Vanguard 1 satellite data collected in the late 1950s.[1][2] The Earth's pear shape as it was known became front-page news and was even the subject of a "Peanuts" cartoon.[3] For that, he is credited as the "father of space geodesy".[4]

He was the first to propose the idea of a scanning microscope in 1956 and he is the co-discoverer of the YORP effect (short for Yarkovsky-O’Keefe-Radzievskii-Paddock effect), an effect resulting from sunlight which causes a small celestial body such as an asteroid or meteor to spin up or down.

  1. ^ O’KEEFE, J. A., ECKEIS, A., & SQUIRES, R. K. (1959). Vanguard Measurements Give Pear-Shaped Component of Earth’s Figure. Science, 129(3348), 565–566. doi:10.1126/science.129.3348.565
  2. ^ Rubincam, David P.; Lowman, Paul D.; Chovitz, Bernard (June 2001). "Obituary: John Aloysius O'Keefe". Physics Today. 54 (6): 76–77. Bibcode:2001PhT....54f..76R. doi:10.1063/1.1387605.
  3. ^ "Peanuts by Charles Schulz for March 16, 1959". GoComics. Retrieved 2022-08-31.
  4. ^ Rubincam, David P.; Lowman, Paul D.; Chovitz, Bernard (2001). "John Aloysius O'Keefe". Physics Today. 54 (6). AIP Publishing: 76–77. doi:10.1063/1.1387605. ISSN 0031-9228.