Emmanuël Jehin is a specialist of the study of the small bodies of the Solar System, and more particularly comets, these small icy bodies¿ remnants of the formation of the Solar System, that are particularly significant in astrobiology, since they may have delivered water and pre-biotic material to the early Earth. He is the leader of the Liège comet¿s physics group and he is involved in several international projects to study comets and also asteroids, trans-neptunian objects and meteors.

He is the project manager of TRAPPIST (TRAnsiting Planets and PlanetesImals Small Telescope), a very successful network of two 60-cm robotic telescopes, one located at the ESO La Silla Observatory in Chile, and the other one at the Oukaimeden Observatory in Morocco. Both telescopes are dedicated to the study of exoplanets and small bodies.

In 2017, these telescopes made the headlines with the detection of a unique nearby planetary system, the TRAPPIST-1 system, composed of seven exoplanets of similar size than the Earth with three of them orbiting in the habitable zone of their star. He is a co-investigator of SPECULOOS (Search for Habitable Planets Eclipsing Ultra-Cool Stars), and was responsible for the installation of the four 1-m robotic telescopes at the Paranal Observatory in Chile.

Passionate about astronomy from a very young age - with the return of Halley's Comet in 1986-, Emmanuël Jehin is deeply involved in the popularization of astronomy, in particular within the Astronomy Group of Spa, that he founded with other enthusiasts in 1990 and which organizes many activities. For 25 years he has been initiating budding astronomers every summer during courses for children, conferences, exhibitions, public observation sessions, etc.