Lunar and Planetary Institute






Constellations

Activity: Zodiac Track


Explore!
Children illustrate the constellations of the zodiac and Polaris and re-create the band of zodiac signs to reinforce their understanding that Earth’s rotation and axial inclination causes the apparent progression of stars across the night sky. Children explore why we see certain signs of the zodiac at certain times of the year in the activity Celestial Circles.

The Activity

With string, tape, and construction paper or poster board, make a large star with one side marked “Polaris” and the other marked “North Star.” Hang Polaris from the ceiling in the middle of the room.

Review with the children the apparent motion of the stars around Polaris in the night sky (Celestial Circles).

  • Do the constellations appear to move across the sky throughout the night?Do all stars appear to move? (All constellations appear to move in a counterclockwise motion around Polaris, the “Pole Star”, which is the
  • only star that appears “fixed.”)
  • Ask the children if they know the zodiac sign associated with their birthdays.
  • How many signs of the zodiac are there?
  • What are the different signs or symbols?
  • Is there a pattern to when the signs of the zodiac are visible?
  • Why are specific zodiac “signs” connected with a particular birthday?

Share with the children that the zodiac is a group of 12 constellations. These constellations form a “band” in the heavens that follows the plane of the ecliptic. The ecliptic is the imaginary plane of the Earth’s orbit about the Sun. There are actually more than 12 constellations contained within the ecliptic plane, but ancient astronomers sited only these 12 as signs of the zodiac.

The children may be familiar with zodiac signs and horoscopes. This is a good time to differentiate between astrology (the belief that celestial bodies have an influence on humans) and astronomy (the science that deals, in part, with the observations of celestial bodies). As the children will learn, there are connections between visible zodiac constellations and the time of year. Refer to “About Polaris” for more information.

Provide each group with the materials and invite them to illustrate a constellation. Let them choose a constellation or use their birthday constellation — but each group should select a different constellation.

Invite each group to reproduce their constellation, using their imaginations and the images provided. For best results, they should make their constellation big enough to fill the black paper, and the stars should be about the size of dimes. Ask them to connect dots with a thin line of glue to outline the shape of the constellation and write the name of the constellation with the glue as well.

Note that the posters will need to dry overnight.

After the constellations have dried, invite the children to hang their posters around the room — spaced evenly across all the walls — in the order in which they are actually positioned on the ecliptic. Starting from Aries and going east, they are Aries, Leo, Sagittarius, Taurus, Virgo, Capricornus (sometimes known as Capricorn), Gemini, Libra, Aquarius, Cancer, Scorpius (sometimes known as Scorpio), and Pisces.

It is useful to know the 12 constellations in their correct order so that, in spotting one, a child can use it as a reference point in locating the others. Challenge the children to create an acronym or jingle to help them remember the constellation order.

  • Do the children recall why Polaris is special? (It is called the Pole Star because in the northern hemisphere, Earth’s north pole points toward it)

Choose one child to represent Earth and position her underneath Polaris.

Have the Earth (child) extend one arm directly toward Polaris. Now have the children observe the Earth as she slowly rotates, turning her head.

  • What does the arm of “Earth” represent? Why is Earth spinning?(Earth rotates through day and night with the northern “axis” pointing to Polaris)
  • As the Earth turns, does its axis always point to Polaris? (Yes)
  • Invite the children to take turns standing in the center of the room under Polaris. Turn off the lights for the full effect of the glow-in-the-dark constellations. What do they observe about the constellations as they/Earth rotate?
  • Are the constellations moving? (No)
  • What is changing?(Earth is rotating)
  • Do we see all the constellations in a single night? (No; when it is daylight, we can’t “see” the stars of the constellations in some parts of the sky even though they are in place)
  • Is there a pattern to which constellations we see?(Yes, we see some during some times of the year, and others during other times)

Invite the children to speculate about why we see some zodiac constellations during some times of the year and others during different times. What are some other changes that the Earth goes through each year? What causes them? Celestial Circles further investigates the annual changes in the night sky.

 

More Activities

 

Who?
Ages 8–14

How Long?
2 sixty minute sessions on different days

What's Needed?

•Books or illustrations of constellations (e.g., Enchanted Learning

For each group or pair of children:

• Tape
•Glow-in-the-dark glue
•Chalk, crayons, or tempura paint in different colors
•A sheet of black poster board or butcher paper.

Connections to the
National Science Standard(s)

tandards A, B&D (grades K–4): Understand and communicate that objects in the sky, such as stars, have patterns of movement on a nightly and yearly scale, caused by Earth’s rotation and orbit. The position of objects in the sky can be described by locating them relative to another object or the background. 

Standards A&D (grades 5–8): Understand and explain that the objects in our solar system are in regular and predictable motion. Apparent movement of the stars in the night sky is due to Earth’s own rotation on its axis and its orbit around the Sun.