Title: Oreo Cookie Phases of the Moon

Principles Investigated:

Moon phases, Moon geometry, Lunar cycles, Orbit of the moon

CA State Standard:

8th grade Physical Science

4d. Students know that stars are the source of light for all bright objects in outer space and that the Moon and planets shine by reflected sunlight, not by their own light.

Materials Needed:

1. Paper plates
2. Markers
3. Plastic Knives
4. Oreo Cookies
5. Earth Cookie

Procedure:

• Using their plastic knives, students should carve out each of the eight primary phases of the moon using the creamy half of Oreo cookies as a model.
• After each phase has been designed, students should be arranged on a paper plate in proper order and in the correct direction of the Moon’s orbit as it revolves around the Earth.
• Student’s will identify from which direction the rays from the Sun are coming from by using a yellow or orange marker to color along the corresponding edge of their plate.
• The direction of the moon as it makes its orbit should be labeled as well as the given names for each of the eight identified phases.

Student’s Prior Knowledge:

Prior to this lab, students should already be familiar with the origin, properties and major features of the moon. They would have also been exposed to the moon’s motions and that it is the only satellite of Earth that orbits around it.

Explanation

Students should be given a handout with a model of the Moon as it goes through its different phases. For this lab, the students will need to re-create the eight primary phases and shapes the moon goes through each month using ½ of an Oreo cookie for each phase. Once all shapes have been created, they should be placed sequentially on their individual paper plates and with labels for each of the corresponding phases. Students will also be expected to properly label the direction from which the light from the sun is emanating, the position of Earth and the direction in which the Moon is headed during it’s orbit.

Questions and Answers

• Why is it that the tides are noticeably more extreme during the New and Full Moon phases?

During the full and new moon phases, the moon is in a state of syzygy where the moon, earth and the sun are in a straight line. This increases the gravitational pull on the ocean’s tides making them more extreme. These are called the Spring tides.

• How and why would the observations of the moon phases differ depending on if you are in the Northern or Southern Hemisphere?

The different shapes created by the moon’s changing phases would appear to be upside down in the Southern Hemisphere compared to the view in the Northern Hemisphere.

• The Synodic lunar month is an average of 29 days while the Sidereal lunar month averages 27 days. How is this discrepancy in time possible?

This difference is caused by the fact that the Earth-Moon system is orbiting around the Sun at the same time the Moon is orbiting around the Earth. While it takes an average of 29 days for the moon to complete it’s cycle going from new moon to new moon, it only takes an average of 27 days for the moon to complete its orbit around the Earth with regards to a fixed, distant star.

• If there is a New moon today, what part of the phase will you expect the moon to be in next week?

In one week the moon completes about a quarter of its orbit, so next week the moon should be in its first quarter with half of its surface illuminated.

Applications for Everyday Life

• Understanding the lunar cycle is important for understanding the influence the moon has on the ocean’s tides.
• Understanding the lunar cycle can be used as a guide for planting and fishing practices.

References

Color image of moon phases

http://www.moonconnection.com/moon_phases.phtml

You Tube video, Why Does the Moon Look Like It Changes?

http://www.youtube.com/watch?v=YdI1aDjWLlY&feature=player_embedded

Lunar Phase simulator

http://astro.unl.edu/naap/lps/animations/lps.html

Wikipedia Lunar Phases

http://en.wikipedia.org/wiki/Moon_phase

Moonstruck Worms

http://www.bio-pro.de/magazin/thema/04228/index.html?lang=en&artikelid=/artikel/04651/index.html

Black and white image of moon phases

http://www.nextfullmoon.info/moon_phases.html

Image of Oreo moon phases

http://tjramadan.talibiddeenjr.amanahwebs.com/05-recipes-ramadan-kids-ore-moon-phases.htm