Charon Tectonics Reveal 14.3-Hour Early Spin and 30-36 km Ice Shell

3 articles · Updated · Nature.com · Jul 14

A new analysis of Oz Terra links Charon’s arcuate mountain ranges and extensional faults to early despinning, preserving one of the clearest tectonic records yet of a moon’s slowing rotation.
Modeling two thrust faults from New Horizons topography indicates a minimum elastic ice-shell thickness of 30-36 km and about 1% east-west compressive strain near the equator.
That strain implies Charon once rotated every roughly 14.25 hours, far faster than its current 153.3-hour tidally locked period with Pluto.
The mapped thrusts appear older than Charon’s later global extension and cryovolcanism, suggesting despinning and mild global contraction shaped the surface within 1-10 million years after formation.
Researchers say the thick early shell and contraction favor a cold-start origin for Charon, offering clues to the thermal evolution of icy worlds across the outer Solar System.