Scientists have long been puzzled by Mercury’s irregular surface. Now, research suggests that the Sun’s gravitational tidal forces may be responsible for the planet’s twisted and fractured landscape. A team from the University of Bern built physical models to examine how the Sun’s gravity affects Mercury’s crust.
The Sun’s gravity causes Mercury to experience fluctuating tidal stresses as it orbits around the Sun. This unique spin-orbit resonance creates a three-and-a-half rotational cycle for every two orbital cycles, resulting in extreme tidal forces that strain the planet’s outer shell. Lead researcher Liliane Burkhard believes these tidal stresses may be guiding Mercury’s tectonic activity.
While the stresses alone are not strong enough to create faults, their directional alignment matches fault-slip patterns observed on Mercury today. This suggests that tidal forces have been quietly shaping the planet’s surface for billions of years.
The implications extend beyond Mercury, offering insights into planetary evolution and geological processes. The upcoming BepiColombo mission, set to launch in 2025, aims to capture unprecedented details of Mercury’s terrain, magnetic field, and internal structure. This data may confirm whether tidal forces are responsible for some of the planet’s most enigmatic features.
Understanding how planets like Mercury deform can help us grasp the evolution of planetary bodies over billions of years.
Source: https://dailygalaxy.com/2025/06/mercurys-surface-is-twisting-like-paper