2026 Study Puts Mercury’s Global Contraction at 6.3 Kilometers, Reviving 7-Kilometer Case
Updated
Updated · spacedaily.com · Jul 18
2026 Study Puts Mercury’s Global Contraction at 6.3 Kilometers, Reviving 7-Kilometer Case
2 articles · Updated · spacedaily.com · Jul 18
Summary
A machine-learning-assisted 2026 analysis estimated Mercury’s global contraction at about 6.3 kilometers when wrinkle ridges are counted, versus about 1.2 kilometers when they are excluded.
The split reflects the core scientific dispute: whether smaller ridges in volcanic plains record planet-wide compression from cooling or mostly local flexure and shallow faulting.
MESSENGER-era work in 2014 had supported shrinkage of as much as 7 kilometers, while earlier Mariner 10-based estimates and a 2021 reassessment favored roughly 1 to 2 kilometers.
The new study also places Mercury’s fastest contraction between about 4.1 billion and 3.9 billion years ago, with later movement slowing sharply rather than continuing at an observable modern rate.
BepiColombo, due to begin Mercury orbit insertion in November 2026 and full science operations in April 2027, is expected to sharpen estimates with new imaging, gravity and magnetic data.