Scientists have produced the first global map and analysis of small mare ridges (SMRs) on the moon, a characteristic geological feature of tectonic activity. Published in The Planetary Science Journal Dec. 24, 2025, the analysis performed by scientists at the National Air and Space Museum’s Center for Earth and Planetary Studies and colleagues reveals for the first time that SMRs are geologically young and are widespread across the lunar maria—the vast, dark plains on the moon’s surface. The team’s discovery of how SMRs form introduces a new set of potential moonquake sources that could affect future site selections for lunar landings.