Mercury Has Shrunk by Several Kilometers Over Billions of Years, Scientists Report

Aug 19, 2025 - 19:00
Mercury Has Shrunk by Several Kilometers Over Billions of Years, Scientists Report
Mercury’s surface reveals it has been shrinking for billions of years due to cooling and faulting. A new study estimates the planet’s radius has contracted by 2.7–5.6 kilometers, offering the most precise figures yet. The findings sharpen understanding of Mercury’s thermal evolution and could help scientists apply the same techniques to tectonic studies on Mars and other rocky planets.