Portrait of Joshua Pepper in a vest, blue tie, and light blue dress shirt.

Joshua Pepper

Deputy Program Scientist, Deputy Program Officer, Program Scientist

Joshua Pepper is a Program Scientist for APD while on academic leave as a professor in the Physics Department at Lehigh University in Bethlehem, PA. He is the Deputy Program Scientist for the Habitable Worlds Observatory, NASA’s next flagship-scale astrophysics mission after the Webb and Roman space telescopes.  He is also the lead Program Officer for the Astrophysics Data Analysis Program (ADAP).  Previously, he was the Program Scientist for the Transiting Exoplanet Survey Satellite (TESS) mission, as well as a Deputy Program Scientist for the Exoplanet Exploration Program.

Pepper received his undergraduate degree in Astrophysical Sciences from Princeton University in 2000, after working with advisors including Bohdan Paczyński, David Spergel, and Michael Strauss. He then attended graduate school in Astronomy at The Ohio State University, where he began working with Andrew Gould on photometric surveys for transiting exoplanets, developing the theoretical description of wide-field transit surveys. Based on that theoretical work, he built a small robotic telescope to conduct a transit survey called the Kilodegree Extremely Little Telescope (KELT), installing the first KELT telescope in Arizona in 2005.

After receiving his PhD with advisor Richard Pogge in 2007, Pepper took a postdoctoral fellowship at Vanderbilt University, working with Keivan Stassun to expand the KELT project with a second telescope in South Africa. By 2010, the KELT project expanded to include a number of graduate students and postdocs, and was identifying its first transit candidates. In 2012, the first KELT planet discoveries were published, and by 2020 KELT had discovered 26 exoplanets, with the majority of them being hot Jupiters orbiting hot or evolved host stars. In 2013, Pepper became an assistant professor at Lehigh University, and was promoted to associate professor in 2019.

Besides KELT, Pepper has worked on a number of projects investigating exoplanets and stellar astrophysics. He was a member of the SDSS-III collaboration, working on the MARVELS and APOGEE surveys, and worked extensively on the LSST project within the Transient/Variable Stars and Milky Way / Stellar Population science collaborations. Beginning in 2010, Pepper joined the TESS Science Team, and with Dr. Stassun he led the creation of the TESS Input Catalog (TIC) and oversaw target selection for the TESS Prime Mission.

Pepper’s expertise lies in wide field astronomical surveys, exoplanet science, and stellar variability. He is an advocate for citizen science, small telescope observing, and open data practices.