Growing up in Colombia, Juliana García-Mejía split time between helping to repair equipment at her maternal family’s fitness business and gazing up at the stars from her paternal family’s coffee farm. She credits this eclectic upbringing with preparing her, in part, to be the principal investigator of the Tierras Observatory atop Mt. Hopkins, Arizona. While earning her Ph.D., Juliana was charged with transforming a once-shuttered 1.3-m telescope for new service. She led all aspects of the design, construction, and recommissioning of Tierras, an exquisitely precise, fully automated photometer that accelerates the discovery of terrestrial exoplanets orbiting small, cool stars called M-dwarfs. The improvements Juliana led include a novel optical system that allows the telescope to image a larger swath of sky, a custom filter that declutters atmospheric effects like water vapor from images, and a robotic mode to capture data night after night.

During her fellowship, Juliana will use Tierras to find Earth-like planets around M-dwarf stars, undertake a systematic search for moons and rings around exoplanets, and study the stars themselves to understand their impact on the planets they host. In tandem with this work, Juliana will design a next-generation, high-resolution instrument with the goal of one day enabling oxygen detection in exoplanet atmospheres. Her research will bolster the census of newfound worlds—prime targets for the James Webb Space Telescope to probe for signs of habitability. Juliana will receive a Ph.D. in astronomy and astrophysics from Harvard University in Spring 2023.

“Most Ph.D. students do not get the opportunity to build something as comprehensively as I did. It was high risk, but it made my eureka moment—seeing that first image after Tierras came online—so special.”