PHASES OF THE MOON

We see the moon because the Sun shines on it We see the moon because the Sun shines on it. The sunlight bounces off or reflects off the moon and onto the Earth. We see the reflected sunlight.

Regular changes of how the moon looks from the Earth are called the phases. Sometimes the moon looks completely dark and seems to disappear. This is called a new moon. Sometimes the moon looks round. This is called a full moon.

Phases of the Moon After the new moon, the moon appears to change. More and more of the moon starts to show. This is a crescent moon. When the moon is growing larger, we call this a waxing moon.

A complete orbit of the moon around the Earth produces the moon’s phases that we see. This complete cycle of the moon’s phases takes about 28 days.

The Moon Facts about the Moon… We see the moon changes its appearances and position in the sky in a monthly cycle. Unlike the stars, Moon can also be seen during the day. We also see that the Moon is always involved in eclipses. Its position relates to the rise and fall of the tides Understanding the motion of the Moon with respect to the Sun and the Earth will explain these phenomena. The moon revolves around the earth with a period of about 29 ½ days ~ one month!

Motions of the Sun-Moon-Earth System Earth orbits the Sun every 365 ¼ days Moon orbits Earth every 28 days

The Face and Phases of the Moon The phase (how much and which side of the Moon is illuminated) of the Moon changes with about one month period… The face (the features on the surface of the Moon) does not change at all… http://s2.thisnext.com/media/230x230_no_border/Faces-on-the-Moon-Stress-Balls_EC142EBB.jpg

The Phase of the Moon The phase of the Moon depends on the relative position between the Sun, the Earth, and the Moon…

Why do we always see the same side of the Moon? The rotation period of the Moon is similar to the revolution of the Moon around the Earth. Is this a coincidence? No!  Objects very closely linked by gravity will eventually “lock” into a certain type of position. The same side of the Moon always faces the Earth.

Phases of the Moon

New Moon

Waxing Crescent

First Quarter

Waxing Gibbous

Full Moon

Waning Gibbous

Last Quarter

Waning crescent

Resources http://highered.mcgraw-hill.com/sites/0072482621/student_view0/interactives.html Chapter 9: http://highered.mcgraw-hill.com/sites/0072482621/student_view0/animations.html# Eclipse Interactive http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::800::600::/sites/dl/free/0072482621/78778/Eclipses_Nav.swf::Eclipse Interactive Lunar Phases Interactive http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::800::600::/sites/dl/free/0072482621/78778/Lunar_Nav.swf::Lunar Phases Interactive http://aspire.cosmic-ray.org/labs/moon/lunar_phase3.swf (Moon phases) http://www.wonderville.ca/v1/activities/phases/phases.html (animated Moon phases) http://www.harcourtschool.com/activity/moon_phases/ (Moon phases)

Review What is a phase? The phases of the Moon occur when …? Does the same side of the Moon always face the Earth? About how long does it take the Moon to orbit around the Earth? About how long does it take for the Moon to make one rotation on its axis? What is the difference between a full moon and new moon?

More Resources Moon Phases: http://home.hiwaay.net/~krcool/Astro/moon/moonphase/ http://www.astro.wisc.edu/~dolan/java/MoonPhase.html http://www.geocities.com/eedd88/moon/moon.html http://www.teachersdomain.org/resources/ess05/sci/ess/eiu/mphase/index.html