
Mercury Shrinks Faster Than Thought, Rewriting Inner-Core Clues
German Aerospace Center researchers estimate Mercury’s global shrinkage is 10–30% faster than previously thought, implying a total contraction of about 7.5–23 km over its history. By combining contraction features with surface roughness maps, they suggest hidden deformation under rough terrain may account for the higher rate, which could indicate a larger or more complex metal core and alter models of Mercury’s geodynamics. The finding uses older MESSENGER data; higher‑resolution maps from ESA’s BepiColombo arriving in 2026 are expected to refine the estimate further.





