Pedro E. Zadunaisky

Pedro Elías Zadunaisky (December 10, 1917 – October 7, 2009) was an Argentine astronomer and mathematician who plotted the orbit of Saturn's most-distant moon, Phoebe, as well as several comets including Halley's Comet, and various satellites including Explorer I.

Zadunaisky was born in Rosario, Santa Fe. He was once a senior astronomer and a mathematician at the Smithsonian Astrophysical Observatory and at NASA's Goddard Space Flight Center.^[1][2] 4617 Zadunaisky is an asteroid named in his honor. He died on October 7, 2009, at the age of 91.^[3] He wrote the book "A Guide to Celestial Mechanics" in 1961.^[4]