Mapping the Moon: Words at the Planetarium

A Map Beneath the Dome

1Zadie and Emil settled beneath the curved ceiling of the planetarium. Today, the dome would display a huge photograph of the Moon rather than a field of stars. Each student received a matching outline map. Their leader, Ms. Voss, explained that lunar means related to the Moon. Their task was to label several features on the lunar surface, the Moon's outer layer.

2Zadie felt apprehensive about marking the wrong places. She held her pencil above the paper without making a mark. Ms. Voss pointed to a bowl-shaped hollow in the photograph. "That is a crater," she said. "Many lunar craters formed when rocks from space struck the Moon." Emil traced the crater's rim, carefully following its edge with his pencil. Then he labeled it on his map.

3The enlarged photograph revealed that the ground was uneven, with ridges and hollows instead of a smooth, flat surface. Zadie aligned her paper with the projected picture so that the same large crater appeared at the top of both. But Emil looked baffled. He could not understand why one side of a crater looked bright while the other side looked dark.

4Ms. Voss brought out a small model Moon and a lamp. The lamp illuminated one side, lighting it clearly. The raised edge of a model crater cast a shadow. Emil nodded as he connected the model to the photograph. Ms. Voss slowly turned the model around its axis. "This spinning movement is rotation," she explained. "Watch how the light and shadows change as I turn it."

5Now the partners examined two photographs taken with light falling from different directions. They had to analyze the pictures by studying their parts closely. They noticed that a long shadow could make a shallow hollow look much deeper. Zadie adjusted a label, moving it slightly toward the correct crater. At the end, both maps matched the photograph. Zadie felt satisfied with her careful work.