Mercury is shrinking — as its iron core slowly cools, the whole planet has contracted by up to seven kilometres, wrinkling its surface into cliffs hundreds of miles long

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Mercury carries the record of planetary cooling across its surface. Long, curving cliffs cut through craters and plains because the small planet lost internal heat, contracted and forced sections of its crust over one another. The widely quoted description is that Mercury has shrunk by as much as seven kilometres. That figure comes from a [...] The post Mercury is shrinking — as its iron core slowly cools, the whole planet has contracted by up to seven kilometres, wrinkling its surface into cliffs hundreds of miles long appeared first on Space Daily .