Waxing gibbous Moon. Image 12 of 27. Optical image of a waxing (increasing in apparent size) gibbous Moon 12 days into its 28-day cycle. The lunar pha

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Waxing gibbous Moon. Image 12 of 27. Optical image of a waxing (increasing in apparent size) gibbous Moon 12 days into its 28-day cycle. The lunar phases arise as the Moon's orbit of the Earth shows the Earth-facing side moving into and out of the light of the Sun. This Earth-facing side of the Moon is locked in place by the gravitational influence of the Earth. This results in a lunar day that equals the length of the lunar Earth orbit. On a waxing Moon the day-night line (terminator) marks the lunar dawn. The Moon is gibbous when it is more than half full. Taken in September 2001. A sequence of the monthly cycle of Moon phases is shown on images R340/644-670.

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Size: 3000px × 3000px
Photo credit: © ECKHARD SLAWIK/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: 12, 12-day-, astronomical, astronomy, cosmology, cycle, cycles, cyclical, days, gibbous, lunar, mare, maria, moon, optical, period, periodical, periods, phase, phases, planetary, satellite, satellites, science, sea, seas, sunlight, sunlit, waxing