• Professional Development
• UEN-TV
• Distance Education
• Network
• About UEN

Phases of the Moon

The moon, of course, has no light of its own. It shines because it reflects light from the sun. As the moon orbits the earth, we see different portions of it lit up, and the moon appears to change shape. These changing shapes are called the phases of the moon. These phases take place over just the half of the moon that faces the earth. (Remember, we only ever really see the side of the moon that faces the earth, and we never see the far side or dark side of the moon.) So over the course of a month which is 29.5 days, the moon changes from new (which means you can't see it at all) to1st quarter (which means you see half of the part of the moon that faces us) to full (which means you see all of that half that faces us) to last quarter (which means you see the other half of the part that faces us) and then back to new again. Get it? So in other words, when the moon is new, it means that the sun is shining on the dark side that we never see. When the moon is full, the sun is shining fully on the side that we always see. When the moon is at 1st quarter, the sun is shining on only half of the part of the moon we can see.

A picture is better than words. Come and visit the following image-intensive internet resources to figure out the phases of the moon.

1. This site gives you the current phase of the moon for this very day. You can also change the calendar to other days. In what phase will the moon be on January 1, 2000? In what phase will the moon be on March 29, 2010? It's pretty cool when there is a full moon on Halloween. Change the date to October 31st. Now start changing the year. In what upcoming years will there be a full moon or the closest thing to a full moon on Halloween?

1. Scroll down about one-fourth of the way on the page to "Viewing the Moon." Click on the choice to view the moon from the earth. From the image that you see (which is a current satellite image), what phase does the moon appear to be in? From the chart, you can see the phase of the moon as a percentage with 100% being a full moon and 0% being a new moon. When is the next new moon? When was the last full moon?

1. Scroll down to "What's Up On the Moon Tonight". You will see today's date and the phase of the moon. What is it? It will be expressed something like "A 19 day old waning moon" which means that it is19 days from the last new moon and getting smaller. (The complete cycle is 29.5 days). Click on the link "Today's Inconsistent Moon Page" to see what a 19 day old waning moon looks like. Have you figured out yet if it is a crescent or gibbous? The site Moon Phases also displays graphical representations of the phases of the moon for today's date or any date you select. Draw todays graphical image.

1. What is a blue moon?

1. Blue moons do not happen every year. 1999 was an unusual year because there were 2 blue moons which is very rare. On what day will there be a blue moon in 2001? On what day will there be a blue moon in 2045?