Study Finds Mercury Shrunk 10%-30% More, Cutting Radius by 7.2 Miles
Updated
Updated · CNN · Sep 10
Study Finds Mercury Shrunk 10%-30% More, Cutting Radius by 7.2 Miles
3 articles · Updated · CNN · Sep 10
Summary
A new Geophysical Research Letters study puts Mercury’s total radius loss at about 7.2 miles, far above many earlier estimates of 0.6 to 4.3 miles.
MESSENGER data drove the revision: researchers mapped surface roughness globally and found impact debris in rugged terrain likely hid contraction wrinkles, making the planet look less shrunken than it was.
That larger contraction could reshape models of Mercury’s interior, pointing to a bigger metal core, fewer light elements in it, or a hotter starting state as the planet cooled.
BepiColombo, due to deploy two Mercury orbiters later this year after an eight-year journey, is expected to test the finding with the first comprehensive global topography and southern hemisphere measurements.