Meet the Fellows Research Detecting helium in exoplanet atmospheres and introducing new possibilities for probing the habitability of faraway worlds. Host University Caltech, Division of Geological and Planetary Sciences Year Awarded 2019 Jessica Spake Ph.D., Astronomy, University of Exeter (United Kingdom) Research Detecting helium in exoplanet atmospheres and introducing new possibilities for probing the habitability of faraway worlds. Host University Caltech, Division of Geological and Planetary Sciences Year Awarded 2019 Upon learning about the detection of hundreds of planets around distant stars during a university lecture, Jessica Spake knew she wanted to dedicate her life to investigating other worlds. Her work centers on characterizing the atmospheres of giant, gaseous exoplanets passing in front of their stars. With a landmark discovery in 2018, Jessica identified helium billowing from a distant planet’s upper atmosphere. This was the first successful observation of helium in a planet outside of our solar system after more than a decade of searching. Jessica’s breakthrough approach uses specific wavelengths of infrared light to distinguish the atmospheric makeup of a planet. This method unlocks new paths for astronomers using ground-based instruments to explore the climates of more planets in the further reaches of the universe. In her fellowship, Jessica will narrow her focus to explore what helium detection can unveil about extreme atmospheric conditions in exoplanets. Using ground-based telescopes, she will target helium in her observations to measure the rate at which exoplanets are losing their atmospheres to space. This information will help improve the field’s understanding about the types of exoplanets that can maintain atmospheres for billions of years—possibly long enough for life to evolve. Jessica received a Ph.D. in astronomy from the University of Exeter in April 2019, and worked as a postdoctoral fellow at John Hopkins University prior to starting her 51 Pegasi b Fellowship. “I am really fascinated by what detections of helium can tell us about the complex conditions of exoplanet atmospheres. Who knows what other interesting things we might be able to see with this new branch of study.”