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10 Cards in this Set

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  • Back

Sidereal month

time it takes for the moon to complete one revolution around earth and return to the same position among the stars (27.3 days)

Synodic or Lunar Month

the time it takes from new moon to new moon (29.5 days)

Solar Eclipse

when the moon blocks the sun, or part of it

Lunar Eclipse

when the earth casts a shadow on the moon


motion of the moon around the earth is called

Geocentric Model

early belief that the earth was motionless and everything revolved around it

Heliocentric Model

sun centered model

The Solar System

complex system of moving masses held together by gravitational forces


the apparent motion, or shift, that occurs between two fixed objects when the observer changes position

Aberration of Starlight

telescopic observations of a systematic change in the position of all stars annually