Although Mercury was geologically active in its early days, today its surface appears almost completely static. This is why it is often perceived as a dead and dry planet. A new study led by Dr. Valentin Bickel from the Center for Space and Habitability at the University of Bern and from the NCCR PlanetS together with researchers from the Astronomical Observatory of Padua (INAF) has now carried out the first systematic analysis of so-called slope streaks, or "lineae." The abundance and distribution of lineae provide new insights into the geological activity of the innermost and smallest planet in our solar system.