# Mercury is shrinking faster than we knew

> New MESSENGER maps show the solar system's smallest planet has lost up to 14 miles, 30% more contraction than astronomers counted.
- Title: Mercury is shrinking faster than we knew · New York Post
- Summary: New MESSENGER maps show the solar system's smallest planet has lost up to 14 miles, 30% more contraction than astronomers counted. Mercury's surface wrinkles…
- Keywords: mercury, planetary science, messenger, astronomy, space, news, entertainment, shrinking, faster, knew, New York Post
- Source: New York Post — https://nypost.com/2026/09/12/science/solar-systems-smallest-planet-shrinking-faster-than-we-thought
- Published: 2026-09-12T20:00:00+00:00
- Read time: 1 min
- Topics: mercury, planetary science, messenger, astronomy, space, news, entertainment
## Mercury is getting smaller
A study in Geophysical Research Letters finds the solar system's smallest planet is contracting about 30% faster than scientists had calculated.

> We are approaching the reality of Mercury's evolution
## A raisin in the sun
Mercury has been shrinking for 4.5 billion years as it cools from its fiery birth. The new figure puts the total loss at as much as 14 miles.
## Small planet, big loss
Mercury is only about 3,000 miles across, one third the width of Earth, so 14 miles off its diameter is a real chunk of the planet.
## Hard planet to watch
Sitting closest to the Sun, Mercury is washed out by glare and bakes at 800 degrees Fahrenheit by day, second only to Venus.
## Counting the wrinkles
MESSENGER orbited for over four years scanning for shortening structures, ridges that pile up as the planet contracts, much like wrinkles with age.
## A trick with two photos
Craters and debris hide many ridges, so Nishiyama combined MESSENGER's dual-imaging shots to cover each patch twice and build a far sharper topographic map.
## Key takeaway

Mercury's surface wrinkles are a record of its cooling interior, and a sharper map of them just revised how much the planet has shrunk by 30%.