The Moon & Its Phases

THE MOON & ITS PHASES

The moon changes visible shape each night.Follows a predictable patternThe shapes are called phasesThe phases last 27 days and 8 hours

The Phases

Begins with NEW MOON (not visible)

WAXING CRESCENT

FIRST QUARTER

WAXING GIBBOUS

FULL MOON

WANING GIBBOUS

LAST QUARTER

WANING CRESCENT

Goes back to new moon and repeats

We all know…

The Earth revolves around the SunThe moon revolves around the Earth

When rotating…The moon always has the same side facing Earth

This is because…It takes an equal amount of time to rotate on its axis…

…as it does to rotate the Earth

The phases we see are the same because of our view point from Earth

What makes the moon visible to us?

The Suns reflection

The moon does NOT make its own light

Depending on what position the moon is in…

…it determines what phase we see

If the moon is on the opposite side of Earth from Sun…

…the sun reflects entire moon on the side we can see

If the moon is between the Earth and Sun…

…the sun’s light hits the moon’s side we can’t see

All the phases

This includes all 8 named phases, plus the shapes in-between the named

phases.

Questions to think about

What are all the phases?How long does it take for all the phases to happen?What makes the moon visible to us?

Citations

Irargerich, “Big Full Moon”, April 21, 2008 via Flickr, Creative Commons License.Minds-eye, “Crescent Moon 7-26-09”, July 26, 2009 via Flickr, Creative Commons License.Dcysurfer, “First quarter luna (with Apollo landing sites)”, February 3, 2009 via Flickr, Creative Commons License.Olibac, “lune/moon”, September 7, 2009 via Flickr, Creative Commons License.Waifer X, “081106-1060460”, November 11, 2008 via Flickr, Creative Commons License.Brron, “13,09,09”, September 13, 2009 via Flickr, Creative Commons License.DraconianRain, “Lunar Dreams (5th to 18th March 2007)”, March 16, 2007 via Flickr, Creative Commons License.