After spending four years as an assistant professor of Planetary Astronomy at Caltech, John Johnson is now a Professor of Astronomy at the Harvard-Smithsonian Center for Astrophysics. In 2012, he was awarded the Sloan Foundation Research Fellowship, the David & Lucile Packard Fellowship, the Feynman Teaching Prize, and the AAS Newton Lacy Pierce Prize for "for major contributions to understanding fundamental relationships between extrasolar planets and their parent stars." In 2013, he was named one of Astronomy Magazine’s “Ten Rising Stars” in astrophysics.

His primary research focus is on the detection and characterization of planets outside our Solar System, commonly known as exoplanets. His most recent work is focused on studying the properties of Earth-like planets around the Galaxy’s least massive stars, commonly known as red dwarfs. His group's notable discoveries include three of the smallest planets discovered to date, each smaller than the Earth and one the size of Mars. His group's statistical analysis of planets discovered around red dwarfs has revealed that there exist 1-3 Earth-like planets per starthroughout the Galaxy. In addition to papers in professional journals and conferences, his work has been featured in the magazines Sky & Telescope, Astronomy, Discover and New Scientist. He blogs regularly at this URL and you can follow him on Twitter as @astrojohnjohn.