Unit 2 Earth, Moon, and Celestial Cycles

What is gravity?

• A type of energy

• A force that causes objects to repel each other

• A force that causes objects to attract each other

• A large celestial object, such as a planet or star

The sun’s gravity helps:

• keep the moon in orbit around the Earth

• keep the Earth in orbit around the Sun

• to shape the Earth as a sphere

• to control the tides on Earth

Which statement below is NOT true?

• The Earth’s gravity keeps the moon in orbit around the Earth

• The moon exerts gravity

• The moon’s gravity pulls on Earth’s ocean waters

• The moon’s gravity keeps the Earth in orbit around the Sun

What motion is responsible for night and day?

• The rotation of Earth

• The rotation of the moon

• The revolution of Earth around the Sun

• The revolution of the moon around the Earth

What motion is responsible for the seasons?

• The rotation of the Sun

• The rotation of the Earth

• The revolution of Earth around the Sun

• The revolution of the Sun around the Earth

What results from the movement of the moon around Earth?

• night and day

• the seasons

• phases of the moon

• high and low tides

What are time units used for?

• To measure the distance between objects

• To measure the temperature of the Sun

• To measure how long it takes natural cycles to occur

• To measure the size of stars, planets and moons

What is the smallest unit of time?

• Year

• Month

• Day

• Second

How long does it take the Earth to make one complete rotation?

• 24 seconds

• 24 hours

• 24 days

• 365 days

What celestial cycle results from the Earth’s revolution around the Sun?

• Seasons

• Day and Night

• Lunar Cycle

• Tidal Cycle