The Moon 7 th Grade Science Ms. Fauss

Motions of the Moon Just like Earth, the Moon rotates and revolves. –What does the Moon revolve around? Earth It takes the same amount of time for the Moon to make one rotation as it takes for the Moon to make one revolution. –27.3 days

Motions of the Moon What does this mean? Because the two motions take the same amount of time, the same side of the Moon always faces Earth.

Reflection of the Sun The Moon looks like it shines because its surface reflects sunlight. Half of the Moon is lighted while the other half is dark. As the Moon revolves around Earth, you see different portions of its lighted side. This causes the Moon’s appearance to change.

Phases of the Moon The phase of the Moon depends on the relative positions of the Moon, Earth, and Sun. A new moon occurs when the Moon is between Earth and the Sun. During a new Moon, the lighted half of the Moon faces the sun; the dark half faces Earth.

Waxing Phases After a new moon, the phases begin waxing. Each day after a new moon, more of the moon becomes visible during the waxing phases. (The illuminated side is on the right) This occurs until a full moon happens. During a full moon, the entire surface of the Moon facing Earth is illuminated.

Waning Phases After a full moon, the phases begin waning. Each day after a full moon, more of the moon becomes darkened during the waning phases. (The illuminated side is on the left) This occurs until a new moon happens.

Moon Phases It takes about 29.5 days for the Moon to complete its cycle of phases.

Eclipses The revolution of the Moon causes eclipses. Eclipses occur when Earth or the Moon temporarily blocks the sunlight from reaching the other. Can only occur when the Sun, the Moon, and Earth are lined up perfectly.

Solar Eclipses Occur when the Moon moves directly between the Sun and Earth and casts its shadow over part of Earth. The darkest portion of the Moon’s shadow is called the umbra. The lighter shadow on Earth’s surface is called the penumbra. People in the area of the umbra experience a total solar eclipse. People in the area of the penumbra experience a partial solar eclipse.

Solar Eclipses

Lunar Eclipses Occurs when Earth’s shadow falls on the Moon. Also has an umbra and penumbra. When the Moon moves completely into Earth’s umbra the Moon goes totally dark, which is a total lunar eclipse. A partial lunar eclipse occurs when only a portion of the Moon moves into Earth’s umbra.

Lunar Eclipses

The Moon’s Surface Contains many depressions called craters. Craters occurred when meteorites, asteroids, and comets struck the surface of the Moon. Upon impact of these things, cracks may have formed in the Moon’s crust. This allowed lava to reach the surface and fill up the craters. The resulting dark, flat regions are called maria.

Tides The gravitational forces between the Earth and the Moon causes our ocean tides. During full and new moons the gravitational forces of the Sun and Moon combine to produce the highest tides called Spring Tides. During quarter moons the gravitational forces of the Sun and Moon oppose each other to produce the lowest tides called Neap Tides.

Tides