Luc Illien is an environmental geophysicist and seismologist collaborating with the Earth Rover Program to help adapt seismic methods to the assessment of soil properties. As a researcher at the GFZ Potsdam in Germany, he focuses on tracking soil moisture and groundwater in mountainous environments and developing new geophysical monitoring techniques. With the ERP, he explores the use of sounds for probing soils and facilitating field work in France.