The document discusses solar and lunar eclipses. It provides an animation of a total solar eclipse and warns that it is unsafe to look directly at one. It explains that a solar eclipse only occurs in the small area that falls within the moon's shadow on Earth. The document also contains a diagram of a lunar eclipse showing the moon passing through the Earth's shadow, which is safe to view directly and sometimes causes the moon to appear red during totality. It notes the difference between observing a total or partial eclipse depending on whether one is located in the umbra or penumbra of the shadow. Finally, it presents an animation of a total lunar eclipse from beginning to end.