Locking of the larger body Tidal locking

the tidal locking effect experienced larger body a, @ slower rate because b s gravitational effect weaker due b s smaller mass. example, earth s rotation gradually being slowed moon, amount becomes noticeable on geological time revealed in fossil record. current estimations (together tidal influence of sun) has helped lengthen earth day 6 hours current 24 hours. currently, atomic clocks show earth s day lengthens 15 microseconds every year. given enough time, create mutual tidal locking between earth , moon, length of day has increased , length of lunar month has shortened until 2 same. however, earth not expected become tidally locked moon before sun becomes red giant , engulfs earth , moon.

for bodies of similar size effect may of comparable size both, , both may become tidally locked each other on shorter timescale. example dwarf planet pluto , satellite charon. have reached state charon visible 1 hemisphere of pluto , vice versa. pluto same age planets in solar system.