Oppenheimer attended the Horace Mann School in the Bronx. After graduating in 1990, she attended Columbia University, where she was an I. I. Rabi Science Scholar. She received a B.A. in Physics from Columbia in 1994. In 1999 she was granted a Ph.D. in astrophysics from the California Institute of Technology and spent the following two years at the University of California at Berkeley on a Hubble Space Telescope Postdoctoral Research Fellowship. In 2001, she moved back to New York City to research at the AMNH, where she joined the faculty in 2004. Oppenheimer regularly gives public and professional lectures on astronomical research.