What is Tidal Locking?




The Moon isn’t the only place in the Solar System where this happens. All major moons of Jupiter and Saturn show the same face to their parent. Pluto and Charon are even stranger, the two worlds are locked, facing one another for all eternity. Astronomers call this tidal locking, and happens because of the gravitational interaction between worlds.









How distant? In about 50 billion years, long after the Sun has died, the Earth and the Moon will finally be tidally locked to each other, just like Romeo and Juliet, Fry and Leela, Pluto and Charon. The force of gravity is a powerful thing. Powerful enough to stop a moon in its tracks.


4 Replies to “What is Tidal Locking?”

  1. The balance of liquid (“lava” or otherwise in other bodies) or solid material inside the moon and the occurrence of volcanism once the one’s forming heat and tidal stretching have gone away? There’s all this about “small” moons having so much activity – could the activity of the moon be part of a larger puzzle of what people thought of as small dead objects that aren’t so dead?

  2. Great article, but I have to object to your posting Emily Lakdawalla’s picture titled “The Non-Planets” because it includes Pluto, thereby endorsing one specific view in the ongoing debate over how to define planet and whether Pluto counts as one. To many planetary scientists, Pluto IS a planet; this photo completely ignores their point of view. Furthermore, Lakdawalla tweeted it from New Horizons headquarters on the day of the flyby, a direct insult to the principal investigator of the mission and the many members of the team who DO consider Pluto to be a planet.

  3. And if the earth and moon aren’t destroyed in the Sun’s red giant phase, once the moon’s orbit has increased to the point of mutual tidal locking, the moon earth system will continue radiating gravitational energy and slowly spiral into each other. How long will that take ?

  4. Are the lunar maria due to the tidal forces on the moon? Would tidal locking explain the greater amount of maria on the earth side of the moon?

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