Takeshi Oka (岡 武史, Oka Takeshi, born 1932), FRS FRSC, is a Japanese-American spectroscopist and astronomer specializing in the field of galactic astronomy, known as a pioneer of astrochemistry and the co-discoverer of interstellar trihydrogen cation (H+3).
[3][4] He is now R.A. Milliken Distinguished Service Emeritus Professor, Departments of Astronomy and Astrophysics, Chemistry; Enrico Fermi Institute; and the College of University of Chicago.
His research group is concerned with the study of the quantum mechanics and dynamics of fundamental molecular ions and their behavior in astronomical objects.
which is thought to be the starting point for gas phase chemistry in interstellar "molecular clouds.
"[6] Following a lengthy search Thomas R. Geballe and Oka detected the infrared spectrum of H+3 in two interstellar clouds.