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Astronomy & Space vocabulary · The Night Sky & Measurement

Lunar phase

Meaning in astronomy & space, with examples

nounCommon term

In astronomy & space, lunar phase means: One of the changing shapes of the Moon's lit part as seen from Earth during a cycle of about 29.5 days, from new Moon to full Moon and back.

In Turkish: Ay'ın evresi, Ay evresi

How it is used

Usually plural: 'the phases of the Moon'. The main phases are new Moon, first quarter, full Moon and last quarter, with crescent and gibbous shapes in between. 'Waxing' means growing and 'waning' means shrinking.

Example sentences

  1. Lunar phases are caused by the changing angle between the Sun, Earth and the Moon, not by Earth's shadow.

  2. Plan your deep-sky observing around the lunar phase and choose nights close to the new Moon.

Common collocations

  • the phases of the Moon
  • lunar phase calendar
  • waxing crescent
  • waning gibbous
  • first quarter
  • moonA natural object that orbits a planet or a dwarf planet. Written as 'the Moon', it means Earth's only natural satellite.
  • eclipseAn event in which one body in space blocks the light of another, for example when the Moon passes between the Sun and Earth, or Earth's shadow falls on the Moon.
  • tidally lockedDescribes 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.
  • SunThe star at the centre of our solar system. Its gravity holds the planets in their orbits, and its light and heat make life on Earth possible.

More terms: The Night Sky & Measurement

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