Homework #4. sun Bemine

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1 IDS 102 Homework #4 Name 1. Why is it warmer (on the average) in Auburn in July than it is in Auburn in January? Explain your reasoning. (Draw a diagram if that will help!) 2. A new planet has just been discovered in a distant galaxy! We have called it Bemine. It appears that Bemine rotates around an axis as illustrated in the diagram below. Where you think the warmest part of Bemine will be? How about the coldest? Why? (Assume the distance to its sun is the same as the Earth s and the greatest diameter through Bemine is about the same as the Earth s diameter.) Axis of rotation sun Bemine The animations you used in both the Phases of the Moon module and the Season module were created by the one and only, Keith Clay. Sometimes another perspective can help you understand an idea. To help us understand the phases of the Moon go to the following University of Nebraska web site entitled Lunar Phase Simulation : As you open the Lunar Phase Simulation, you will notice the check boxes in the lower center of the web page. Click the following items: show phase panel show observer show lunar landmark do not click on show angle show time tickmarks The animation starts with a New Moon. Notice that the Moon is between the Earth and the Sun at this phase of the Moon. Rarely the Moon is directly between the Earth and the Sun and we see a solar eclipse. Most of the time, although the Moon is between the Earth and the Sun, the Moon is not in the same plane as the Earth and the Sun and there is no eclipse.

2 In the lower right part of the web page is a figure (similar to the one below) that shows our perspective of the Sun and the Moon. This is the type of view that early observers of astronomy had when they thought the Earth was the center of the universe. As you change the time as a part of the simulation, the Sun and Moon will appear to orbit the Earth. Of course, only the Moon orbits the Earth, but from our perspective, it appears everything orbits us. The large diagram in the middle of the page shows the real situation. Click on hour + to move the time of day to 6:00 PM (sunset). In the diagram in the lower right, the Sun is shown as a yellow circle and the moon is a dark gray circle. Once the time is at 6:00 PM, notice the position of the Sun and Moon in the diagram on the lower right. Sun Click on day + to advance the scene to the next day at the same time. Click this button five times and note on the figure on the previous page and in writing in the space below how the positions of the Moon and the Sun have changed or not changed at the same time of day.

3 We recommend playing with this animation to see a different type of animation for the phases of the moon. When the Moon looks like this draw the position of the Sun, Earth, and Moon in the space below: When the Moon looks like this draw the position of the Sun, Earth, and Moon in the space below: How much of the Moon is being illuminated by the Sun when the Moon appears like the illustration below? So, explain why we see the Moon this way.

4 waxing or waning waxing or waning How could you tell the difference? Is the following Moon, waxing or waning? For each of the Moons below, determine the position of the Moon, Earth, and Sun, the phase of the Moon, and what the Moon would look like 7 days later: position of Sun, Moon, and Earth waxing or waning name for this phase

5 what will the Moon look like 7 days later? The following statements are either true or false. If the statement is true, defend your choice in the space below. If the statement is false, state why the statement is false. 1. A waxing gibbous moon phase will be a few days before the full moon phase. 2. When the Moon appears as it does below, it is possible to have a lunar eclipse: 3. The time of day we expect to see the following phase of the moon is in the early morning, such as 5 or 6 AM.

6 Planet Keith below rotates around its N-S axis and orbits the sun. The position of Planet Keith is shown at two times during the year. Planet Keith s rotational axis points directly at the sun and north is always pointed toward the sun. a) Will Planet Keith have seasons? Explain your logic. b) Will Planet Keith have day and night? Explain your logic.