Education and
Public Engagement
at the Lunar and Planetary Institute
Explore! Ice Worlds

Ice Zones: Where We Look for Ice

Overview

In this 30 minute activity, children, ages 10 to 16, draw conclusions about where on a planetary body scientists might look for ice — and why. They use a clay ball, ice cubes, and a heat lamp to model the permanently-shadowed polar regions of planets and moons that may harbor ice. They learn that our Moon and even Mercury may have areas with ice!

What's the Point?

Materials

For each group of three to four children:

For the facilitator:

Activity

1. Invite the children to share their ideas about ice.

2. Share the Planetary Themometer cartoon with the children.

Facilitator's Note:There are some exceptions. Neptune's axis is slightly tilted, like Earth's, and its south pole has pointed at the Sun for decades — making it the warmest spot on the planet. Curiously, the one planet that orbits the Sun on its side — Uranus — is not warmer at the pole facing the Sun than at its equator. Scientists are still unsure as to why this might be the case. Saturn's moon Enceladus is also warmer at its south pole than at its equator, due to tidal forces from  Saturn. All of these bodies lie far out in the solar system where their temperatures overall are cooler.

3. Provide the children with clay or styrofoam balls, coffee stirrers or toothpicks, and lamps and invite them to explore why the poles are cold and the equator is warm.

4. Have the children insert one coffee stirrer or toothpick into the north pole and one into the south pole of their clay Moon so that they are sticking out.

5. Invite the children to experiment with creating day and night on the Moon's surface using the lamp and ball. Day and night cycles are produced because a planet or moon spins on its axis.

6. Share that, because the Moon has no atmosphere to help control its temperatures, the Moon's daytime side is very hot (about 225°F / 107°C), and the Moon's nighttime side is very cold (about -244°F / -153°C). Areas in the shade during the lunar day are also very cold. Let the children know also that the Moon turns more slowly on its axis than Earth. The lunar day and the lunar night are each about 14 days long.

7. Share with the children that the Moon's axis is almost straight up and down (it’s only tilted  1.5°). This is much smaller than Earth's axial tilt of 23.5°. As they are creating day and night, make sure they hold the Moon so that the north pole is upright and not tilted.

8. Invite the children to add the rest of their toothpicks or coffee stirrers to their Moon in a line stretching from the north to the south lunar pole. They should be spaced evenly, and sticking out, with one at the equator of their  Moon.

9. Darken the room lights and invite the children to shine their “Sun” lamp at their Moon from two to three feet away, so that the center of the beam of light is aimed at the Moon's equator, then slowly turn their Moon.

10. Have the children brainstorm some ideas about how they might create places that are permanently in shadow on the Moon’s surface. Share the images of the cratered lunar surface.

11. Invite the children to create craters in their moons by poking half-inch-deep holes, including one in the north.

Scientists have found evidence for ice in some of the deep, dark, cold craters at the Moon's north and south poles, at at  Mercury’s poles.

12. Tell the children that two comets are about to strike their Moon. Provide the groups with two ice cubes. Have them place once in a crater at the north pole and one in a crater at the equator. Make sure to push the ice cubes into the ball so that they are beneath the surface with the tops of the cubes exposed. This will help them stay in place.

13. Invite the children to illuminate their Moon, holding the lamp about 5 to 6 inches from the surface, for about three minutes. The child holding the Moon should hold it so that his or her fingers are as far from the ice cubes as possible.

The children may notice that the ice cube at the pole is melting slightly. This is not the case for ice in permanently shadowed regions on the Moon!

14. After three minutes have the children remove the ice cubes and examine them.

Conclusion

Have the children reflect on where ice might be in the solar system based on what they know about ice and what they have learned in the experiment.