Yes. A September 10, 2026 study in Geophysical Research Letters finds Mercury’s cooling-driven contraction has likely been underestimated by about 10% to 30% because impact debris and rough terrain hide many surface wrinkles that record that shrinking.
After correcting for that obscuration, the researchers report radial contraction of up to about 11.6 kilometers—corresponding to roughly 19 kilometers (nearly 12 miles) of diameter loss since the planet formed. Lead author Gaku Nishiyama of the German Aerospace Center said greater shrinking would imply a larger metal core, fewer light elements mixed into it, or a hotter starting temperature. Higher-resolution data from ESA/JAXA’s BepiColombo mission, due to enter Mercury orbit in November 2026, may refine the estimate further.
Source: Space.com — Mercury is shrinking faster than we thought (Sept. 10, 2026)