Mercury's Shrinking Continues, Revealing Wrinkles

A new study suggests that Mercury is still cooling down, leading to tectonic activity on the planet's surface. Vertical faults called "graben" have been identified on Mercury, indicating recent contraction due to cooling. These graben are widespread and suggest ongoing tectonic activity. The cooling process on Mercury can lead to the loss of liquid cores, magnetic fields, and volcanic activity. The study estimates that most of the graben are less than 200 million years old, indicating that the cooling of Mercury is still occurring.