Study Finds Mercury Shrinking Faster Than Previously Estimated
New research indicates that Mercury is losing about 14 miles of its radius, roughly 30% more rapidly than earlier calculations suggested.
A recent analysis published in Geophysical Research Letters reports that Mercury, the solar system’s smallest planet, is contracting at a rate about 30% faster than earlier estimates. The study, led by planetary scientist Gaku Nishiyama of the German Aerospace Center, used high-resolution images from NASA’s MESSENGER spacecraft, which orbited Mercury for more than four years.
By combining overlapping photographs taken by MESSENGER’s dual-imaging system, the researchers created a detailed topographic map that revealed a greater number of surface features associated with planetary shrinkage, known as shortening structures. These features, analogous to wrinkles that appear as a planet cools and contracts, suggest the planet has lost up to 14 miles of its radius since its formation 4.5 billion years ago.
"We are approaching the reality of Mercury’s evolution," Nishiyama said in an email to the Associated Press.
The findings provide new insight into Mercury’s internal composition and thermal history, and may help scientists understand contraction processes on other terrestrial planets.