Mercury Has Shrunk by Several Kilometers Over Billions of Years, Scientists Report
Aug 19, 2025 - 19:00

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.