2. Describe: Months are another unit of time based on an astronomical event. Click Reset, and move the Sim. speed slider to the right a quarter of the way. Click Play, and observe the movements of Earth and the Moon for one month. (Note: You can use the calendar in the upper right corner of the 2D VIEW tab to determine when a month has passed.) A. Describe the movements of Earth and the Moon over the course of a month. B. What astronomical event corresponds to the passage of one month? It takes approximately 28 days for the Moon to revolve around Earth. Revolution is the elliptical motion of a body traveling around another body in space.

To address your request, let's break it down into two parts: A and B. ### A. Describe the movements of Earth and the Moon over the course of a month. 1. **Earth's Rotation**: Throughout the month, Earth continues to rotate on its axis, completing one full rotation approximately every 24 hours. This rotation causes the cycle of day and night. 2. **Moon's Revolution**: The Moon revolves around Earth in an elliptical orbit. Over the course of a month (approximately 28 days), the Moon completes one full orbit around Earth. This means that you will observe the Moon changing its position relative to Earth and the Sun. 3. **Phases of the Moon**: As the Moon orbits Earth, it goes through different phases due to the changing angles of sunlight illuminating its surface. You will see the Moon transition from a new moon (when it is between Earth and the Sun and not visible) to a full moon (when it is on the opposite side of Earth from the Sun and fully illuminated) and back again. 4. **Relative Positioning**: As the Moon moves, its position relative to Earth and the Sun changes, which affects how we perceive its brightness and shape. You will notice that the Moon appears to move across the sky, rising in the east and setting in the west, similar to the Sun. ### B. What astronomical event corresponds to the passage of one month? The passage of one month corresponds to the Moon's complete revolution around Earth. This period is approximately 28 days, which is the time it takes for the Moon to return to the same position relative to Earth and the Sun. This cycle is known as a lunar month or synodic month, and it is based on the Moon's phases, which are a direct result of its orbit around Earth. In summary, the movements of Earth and the Moon over the course of a month involve the continuous rotation of Earth and the Moon's elliptical orbit, leading to the observable phases of the Moon, while the passage of one month is defined by the Moon's complete revolution around Earth.