Occurrence Tidal locking

1 occurrence

1.1 moons

1.1.1 moon


1.2 planets
1.3 stars

occurrence
moons

due tidal locking, inhabitants of central body never able see satellite s green area.

most major moons in solar system − gravitationally rounded satellites − tidally locked primaries, because orbit closely , tidal force increases rapidly (as cubic function) decreasing distance. notable exceptions irregular outer satellites of gas giants, orbit farther away large well-known moons.

pluto , charon extreme example of tidal lock. charon relatively large moon in comparison primary , has close orbit. results in pluto , charon being mutually tidally locked. pluto s other moons not tidally locked; styx, nix, kerberos, , hydra rotate chaotically due influence of charon.

the tidal locking situation asteroid moons largely unknown, closely orbiting binaries expected tidally locked, contact binaries.

the moon

because moon 1:1 tidally locked, 1 side visible earth.

the moon s rotation , orbital periods tidally locked each other, no matter when moon observed earth same hemisphere of moon seen. far side of moon not seen until 1959, when photographs of of far side transmitted soviet spacecraft luna 3.

when earth observed moon, earth not appear translate across sky appears remain in same place, rotating on own axis.

despite moon s rotational , orbital periods being locked, 59% of moon s total surface may seen repeated observations earth due phenomena of libration , parallax. librations caused moon s varying orbital speed due eccentricity of orbit: allows 6° more along perimeter seen earth. parallax geometric effect: @ surface of earth offset line through centers of earth , moon, , because of can observe bit (about 1°) more around side of moon when on our local horizon.

planets

it thought time mercury in synchronous rotation sun. because whenever mercury best placed observation, same side faced inward. radar observations in 1965 demonstrated instead mercury has 3:2 spin–orbit resonance, rotating 3 times every 2 revolutions around sun, results in same positioning @ observation points. modeling has demonstrated mercury captured 3:2 spin–orbit state in history, within 20 (and more 10) million years after formation.

venus s 583.92-day interval between successive close approaches earth equal 5.001444 venusian solar days, making approximately same face visible earth @ each close approach. whether relationship arose chance or result of kind of tidal locking earth unknown.

proxima centauri b, earth-like planet discovered in 2016 orbits around star proxima centauri tidally locked, either in synchronized rotation, or otherwise expresses 3:2 spin-orbit resonance of mercury.

stars

close binary stars throughout universe expected tidally locked each other, , extrasolar planets have been found orbit primaries extremely closely thought tidally locked them. unusual example, confirmed most, tau boötis, star tidally locked planet. tidal locking mutual.