Mercury Lost 14.5 Miles of Diameter, Shrinking 10% to 30% Faster Than Thought
Updated
Updated · Futurism · Sep 14
Mercury Lost 14.5 Miles of Diameter, Shrinking 10% to 30% Faster Than Thought
3 articles · Updated · Futurism · Sep 14
Summary
Scientists estimate Mercury has shed up to 14.5 miles of total diameter since formation, a new revision that puts its long-term contraction 10% to 30% above earlier estimates.
Impact-crater debris may have masked part of that shrinkage: by combining existing surface maps, researchers found the roughest terrain shows fewer wrinkle-like faults, suggesting buried shortening structures.
The faster contraction supports the idea that Mercury cooled like a deflating balloon, cracking its rocky outer layer into scarps and ridges as the interior lost heat.
Those rates could mean Mercury has a larger metal core, fewer light elements mixed into it, or a hotter starting state, sharpening models of how the planet formed and evolved.
BepiColombo — the ESA-JAXA mission launched in 2018 — is due to enter Mercury orbit in November, offering the first close follow-up since only one prior spacecraft orbited the planet.