The Moon and the sun look roughly the same size in the sky because although the sun’s diameter is ~400 times greater than the Moon’s, the sun is ~400 times farther away from the Earth as the Moon is! The Moon goes through phases because as it rotates around the Earth, different parts of the Moon are made visible to us from the sun’s light. Created by Sal Khan.

This lesson is created to introduce students to the relationship between the sun, Earth, and the moon. The movement of Earth and the moon in  relationship to the sun causes phases of the moon.  The interactions and orientation of the sun, Earth, and moon lead to patterns that are evidenced in seasons, eclipses, and the phases of the moon.  There are 8 phases of the moon: New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Last Quarter, Waning Crescent.  The moon grows and disappears backwards (right to left)in its changing of phases. The moon revolves around Earth as the Earth revolves around the sun. The moon takes about one month to complete one revolution around the Earth.

Video Description:  What causes the phases of the Moon? From New Moon to Full Moon, the Earth-Sun-Moon system is responsible for the Moon’s changing phases. Learn more about rotation, revolution and this repeatable pattern. Video Length:  3:13. NASA eClipsTM is a suite of online student-centered, standards-based resources that support instruction by increasing STEM literacy in formal and nonformal settings.  These free digital and downloadable resources inform and engage students through NASA-inspired, real-world connections.NASA eClips Our World videos (grades 3-5) help students understand the differences between science (the natural world) and engineering (the designed world).  These video segments supplement elementary learning objectives not only in science, technology, engineering and mathematics, but also in reading, writing, visual and performing arts.