In February 2017, Julien de Wit PhD ’14 was a member of the international team, led by University of Liège colleague Michaël Gillon, that announced the discovery of seven temperate Earth-sized planets orbiting the red dwarf star TRAPPIST-1. Soon afterward, the team found evidence bolstering the supposition that the outer planets in the system could hold significant stores of water. “It’s amazing how quickly our perspective on this [system] has changed,” de Wit— then a postdoc in the group of Sara Seager, Class of 1941 Professor of Physics and Planetary Science—told MIT News in 2017. “It’s a steep learning curve that is really exciting.” In July 2018, de Wit began a faculty appointment as assistant professor in MIT’s Department of Earth, Atmospheric, and Planetary Sciences (EAPS).
De Wit now leads the effort to characterize the atmospheres of the newly discovered TRAPPIST-1 planets. So far, using the Hubble Space Telescope, his team has ruled out the presence of hydrogen-dominated atmospheres (which would be typical of inhospitable, gaseous planets such as Neptune) for the five innermost planets of the system. These results strengthen the case that Earthlike conditions could potentially exist within the system, and lay the groundwork for more targeted observations via NASA’s James Webb Space Telescope, scheduled to launch in 2021.
De Wit is also involved in the effort to establish an observatory in the Northern Hemisphere (part of a project whimsically dubbed SPECULOOS, after a popular cookie from de Wit’s native Belgium). This new network of telescopes will expand upon the TRAPPIST prototype, continuing the search for new potentially habitable systems.
According to de Wit, “The door now stands open to expanding our understanding of planetary systems, habitats, life, and ultimately our own planet, through the discovery and study of new terrestrial exoplanets that can be characterized in-depth. This has the potential to be paradigm-shifting.”