Mercury is shrinking faster than previously thought

Scientists at DLR's Institute of Planetary Research found that Mercury is contracting 10–30% faster than previous estimates. The planet's diameter has shrunk by about 7.5–23 km instead of the previous 4–16 km, indicating a larger metallic core or higher initial temperature.

• Contraction 10–30% faster than previous estimates
• Diameter shrank by 7.5–23 km instead of 4–16 km
• Cause: craters hide surface folds
• BepiColombo to refine data after arrival on November 21, 2026