Unit 5 Sun, Moon, and EarthSystem Key Vocabulary

Front

Daylight

Back

The amount of light received from the Sun during the day.

Front

Earth

Back

The planet we live on, which orbits the Sun in the solar system.

Front

Gravity

Back

A force that pulls objects toward one another; on Earth, it pulls objects toward the ground.

Front

Moon

Back

A natural satellite that orbits a planet, such as Earth’s Moon.

Front

New Moon

Back

The phase of the Moon when it is not visible from Earth because the side facing Earth is not lit by the Sun.

Front

Waxing Crescent

Back

A small, curved sliver of the Moon becomes visible, increasing in size as it moves toward the first quarter.

Front

First Quarter

Back

Half of the Moon's disk is illuminated and visible from Earth, occurring one-quarter through the lunar cycle.

Front

Waxing Gibbous

Back

The Moon is more than half illuminated but not yet full, as the lit portion grows.

Front

Full Moon

Back

The entire face of the Moon is illuminated and visible from Earth.

Front

Waning Gibbous

Back

The Moon begins to decrease in illumination after the full moon phase.