Study Guide for the Gravity, Seasons, Tides, and Moon Quiz Earth: The Earth rotates on its axis. It takes the Earth 24 hours to complete one rotation. An example of rotation is spinning a ball. One rotation of the Earth causes night and day. The Earth is revolving around the sun. An example of revolution is walking around your chair. One revolution of the Earth takes 1 year. Moon: The moon is revolving around the Earth. One revolution of the moon takes 27.3 days. One rotation of the moon on its axis also takes 27.3 days. The moon phase depends on the position of the Earth, moon and sun. Moon Phases: New Moon Full Moon Waxing Crescent Waning Gibbous First Quarter Waxing Gibbous Last Quarter Waning Crescent Study Guide for the Gravity, Seasons, Tides, and Moon Quiz Seasons: Seasons are caused by the tilt of the Earth and the revolution of the Earth. When our part of the Earth (the Northern Hemisphere) is tilted away from the sun we are experiencing winter. When our part of the Earth (the Northern Hemisphere) is tilted towards the sun we are experiencing summer. Tides: The gravitational pull of the moon has the greatest affect on the Earth’s tides. In most places on Earth there are 2 high tides and 2 low tides every 24 hours. Spring Tide Neap Tide Gravity: Gravity is a type of force. All matter has gravity. The greater the mass of an object the more gravitational pull it has. Gravity keeps the planets orbiting around the sun. Your weight will change on different planets because of gravity. Objects fall because of gravity. Heavy and light objects will hit the ground at the same time if released at the same time.