A new study shows that little, wrinkly Mercury may be shrinking faster than expected. Scientists from the German Aerospace Center reported Thursday that Mercury’s shrinkage may be 30% greater than previously believed. They say that represents a loss in diameter of as much as 14 miles, significant for a planet that is barely 3,000 miles across. Mercury has been shrinking ever since its formation 4.5 billion years ago because of internal cooling, which is tightening the surface like a girdle to fit its new slimmer self.