The moon’s appearance in the sky follows a 29.5-day cycle. During the cycle, it first appears as a crescent. The lighted portion that you can in the night sky see becomes larger as days pass, growing until you see a full moon. As more days pass, the lighted portion gets smaller again, until no moon is seen. The cycle then repeats. This 29.5-day cycle corresponds to the time during which the moon makes one complete orbit around Earth.
When you see a full moon, Earth is between the moon and the sun, and all of the lighted half of the moon faces Earth. When there is a “New Moon.” the moon is between Earth and the sun, and all of the lighted half of the moon faces away from Earth. When there is a New Moon, you can’t see any of the moon at all.
Copies of moon phases (downloadable here!)
Jumbo craft sticks
Fold a paper plate in half and carefully cut out the middle of the plate with scissors.
Neatly cut out the moon phases and glue them to the rim of the plate starting with #1 in the 12 o’clock spot and working clockwise.
Staple a jumbo craft stick to the bottom of the plate.
Staple or glue the moon phase key to the handle of the plate.
At night, locate the moon. Holding the moon viewer with the stick pointing toward the ground, frame the moon within the center of the plate. Observe. Which picture does the moon most closely resemble? Find that number on the moon phase key and you will know the name for the phase of the Moon you are viewing!
Editor’s note: In honor of our new Nautilus Live program — which takes Museum patrons to the ocean floor with telepresence technology — this month’s Educator How-To is all about the nautilus shell. From our veteran Xplorations educator Kat Havens:
It is difficult to deny the beauty and perfection of the nautilus’ spiraled chambers. Many have heard it is a perfect example of a Golden Spiral or have seen pictures of it neatly fitted into a Golden Rectangle. Although compelling, it is mathematical mythology.
The angles found within the chambers of the shell exhibit multiple angles that are not congruent with those of the Golden Spiral. In fact, the spiral of the nautilus is more correctly known as an approximate logarithmic spiral or as exhibiting logarithmic spiral growth. Growing in this manner allows the animal to increase in size without changing its shape. We think that it is an excellent example of Mother Nature’s knack for beautiful symmetry.
• Cut nautilus shell
• Styrofoam or paper plate
• Sheet of craft foam or other padded surface
• Paper – color of your choice
• Acrylic paint – color of your choice
1. Gather all of your supplies. Cut nautilus shells are common and may be purchased at seaside shell shops or found online at a reasonable price. They are reusable, provided they are cleaned promptly after each use. We tried cutting our own shells with a fine saw but, we were not completely satisfied with the results.
2. Place “springy” material, such as craft foam, under the print paper. This allows for a better “pull” as the give in the foam allows for better contact between shell and paper.
3. Pour a good amount of acrylic paint onto the plate. Manipulate the plate by tipping it around until the paint is spread in an even layer that is large enough to accommodate the shell. Place the shell into the paint and pull it out. You will find the paint may coagulate in the smaller chambers and makes an unclear print. This is solved by gently blowing on these chambers to break the paint bubbles.
4. Carefully press the shell onto the paper. Do not move the shell in any direction once contact with the paper is made as it will smear the print. Gently pull the shell up. Often, you can get another decent pull directly after the first print, so feel free to make two or more with one paint application.
Ancient Egyptian artists adhered to strict rules when producing works of art. The human form was depicted with the head in profile, eye drawn in full, torso forward-facing, and legs in profile — one foot in front of the other. This style, known as frontalism, gave the figures a sense of formality. Whether standing or sitting, the subjects appear rigid in pose: gaze set, body stiff.
Red lines represent the system used in the Old Kingdom. The addition of the white graph is indicative of the system used from the Middle Kingdom to the Late Period
Proportions were kept consistent through the use of grids and lines. The earliest examples from the Old Kingdom employed a simple system of horizontal guidelines with one vertical line bisecting the figure though the ear. Beginning with the Middle Kingdom up to the Late Period, a grid of 18 squares was used to reproduce standing figures and to allow the picture to be enlarged or made smaller while ensuring that the proportionality of the figure’s anatomy remained intact.
Paintings were most likely planned on papyrus paper and later transferred to tomb walls by an artisan using the grid system as an aid.
Try your hand at using the grid system to copy an ancient Egyptian work of art! All you need is a copy of the blank grid, a copy of the tomb painting on the grid, and a pencil.
The cubit was Ancient Egypt’s standard unit of measure, much like our foot or meter measurement. There were two cubit lengths in ancient Egypt: the short cubit and the royal cubit. The short cubit was the distance from the elbow to the tip of the middle finger of the pharaoh. The royal cubit was the distance from the elbow to the middle fingertip, plus a palm width.
The ancient Egyptians also had smaller units of measure called the palm and the digit. The palm was the width of your four fingers held close together, and the digit is the width of your index finger. So, to review:
• A cubit is the length from your elbow to the tips of your fingers
• A palm is the width of your four long fingers
• A digit is the width of your finger
We’ve put together a handy little activity to teach your kids about ancient Egyptian units of measurement below:
1. Separate children into pairs. They will take turns measuring each other from elbow to the tip of the middle finger using the measuring tape. They should record this number, as they will need it shortly.
2. Now, using stiff cardboard, students will measure out the same length as their measurement from elbow to fingertip and cut the cardboard to this length in the shape of a standard ruler.
3. They should then divide the cubit into palms and digits using four fingers of the hand for the palm and one finger-width for the digit divisions.
4. Using markers, students should neatly record the following information on their cubit: Their name, length of the cubit in inches, and length of the cubit in centimeters.
5. Ask the class if all of the cubits will be the same length. Why or why not?
6. Record all of the cubit lengths from the entire class and average that number. This could be the standard length of the “class cubit.”
7. Measure different items using your cubit.