Okuzeka
Astronomy & Space vocabulary · Orbits & Gravity

Tidally locked

Meaning in astronomy & space, with examples

adjectiveAdvanced term

In astronomy & space, tidally locked means: Describes a moon or planet that always turns the same face towards the body it orbits, because it spins exactly once for every orbit it completes.

In Turkish: kütleçekimsel olarak kilitlenmiş, gelgit kilitli

How it is used

Used about the Moon, many other moons and exoplanets that orbit close to their stars. The noun is 'tidal locking'. Scientists discuss whether a tidally locked planet, with one side always in daylight and the other always dark, could support life.

Example sentences

  1. The Moon is tidally locked, so we always see the same side from Earth.

  2. Many planets around red dwarf stars are probably tidally locked.

Common collocations

  • tidally locked to Earth
  • tidally locked planet
  • tidal locking
  • moonA natural object that orbits a planet or a dwarf planet. Written as 'the Moon', it means Earth's only natural satellite.
  • orbitThe curved path that an object such as a planet, moon or satellite follows around another object because of gravity. As a verb, it means to move along this path.
  • gravityThe force that pulls any two objects with mass towards each other. It keeps the planets in orbit around the Sun and keeps our feet on the ground.
  • orbital periodThe time an object takes to complete one full orbit around another object. Earth's orbital period around the Sun is about 365.25 days.
  • exoplanetA planet that orbits a star other than the Sun. The first one around a Sun-like star was found in 1995, and thousands are known today.

More terms: Orbits & Gravity

Practise with graded reading

Reading at the right level is the fastest way to make new words stick. Pick free English books by level: