Hidden clues show Mercury shrank more than previously thought

Live updates

1. 2d ago

   Mercury contracted 40% more than visible surface scars indicate

   Mercury shrank more than scientists previously expected as its interior cooled over billions of years. New analysis of masked tectonic structures suggests the planet contracted 40% more than the visible ridges and cliffs on its surface originally indicated. This process caused the rocky exterior to crumple, similar to the skin of a drying fruit, creating the steep cliffs and ridges that define the planet's current topography. Researchers are now investigating if the planet is even smaller than these updated estimates suggest.

   Why it matters

   The size of a planet is tied to the thermal state of its core. Understanding Mercury's contraction helps scientists model how planetary interiors cool and affect surface geology over time.

   What is confirmed

   • Mercury shrank as its interior cooled over billions of years.
   • The planet's rocky surface crumpled into ridges and cliffs during contraction.
   • Mercury shrank more than scientists previously thought.

   Still unconfirmed

   • Masked tectonic structures suggest Mercury contracted 40% more than its visible scars alone indicate.
   • Scientists are investigating if Mercury is even smaller than current expectations.

   What to watch next

   • Verification of tectonic structure data by independent planetary science teams.
   • New measurements of Mercury's current diameter to confirm total contraction volume.
   Sources used for this update (7)

   1. USA Today — Hidden clues show Mercury shrank more than previously thought
   2. The New York Times — Mercury Is Shrinking, and Faster Than We Thought
   3. Time Magazine — The Planet Mercury Has Been Shrinking—More Than Scientists Expected
   4. CNN — Scientists are trying to figure out if Mercury is even smaller than expected
   5. AGU Newsroom — Mercury is shrinking more than we thought
   6. scitechdaily.com — A 400-Degree Mystery Is Hiding Deep Inside Mars
   7. Phys.org — Masked tectonic structures suggest Mercury contracted 40% more than its visible scars alone indicate
   confidence 90%