Franklin was the chief scientist at the Hayden Planetarium from 1956 to 1984 and was co-credited with discovering radio waves originating on Jupiter, the first detection of signals from another planet.

[1][2] He was often a local and national media figure including during Apollo 11, the first human mission to the moon, when Franklin was an on-camera astronomy expert for NBC.

On May 18, 1958, he married Charlotte Walton, who worked at Carnagie in the terrestrial magnetism dept., and later legally adopted a daughter from her previous marriage.

He also lectured at Columbia School of Journalism and the United States Military Academy and was an adjunct professor at Rutgers University for three and a half years.

Franklin was part of a visiting lecturer program and in 1973 and 1980, he led tours to Africa to observe solar eclipses.

[2] He was a member of the all-male literary banqueting club the Trap Door Spiders, which served as the basis of Isaac Asimov's fictional group of mystery solvers the Black Widowers.