Observing Projects
Use a telescope or binoculars to observe craters on the Moon. Make a drawing of the Moon, indicating the smallest and largest craters that you can see. Can you estimate their sizes? For comparison, the Moon as a whole has a diameter of 3476 km. Hint: You can see craters most distinctly when the Moon is near first quarter or third quarter (see Figure 3-2). At these phases, the Sun casts long shadows across the portion of the Moon in the center of your field of view, making the variations in elevation between the rims and centers of craters easy to identify. You can determine the phase of the Moon by looking at a calendar or the weather page of the newspaper, by using the Starry Night™ program, or on the World Wide Web.
Use Starry Night™ to examine magnified images of the terrestrial major planets Mercury, Venus, Earth, and Mars, and the dwarf planet Ceres. Select each of these planets from Favourites > Explorations in turn. Use the location scroller cursor to rotate the image to see different views of the planet. (a) Describe each planet’s appearance. From what you observe in each case, is there any way of knowing whether you are looking at a planet’s surface or at complete cloud cover over the planet? (b) Which planet or planets have clouds? If a planet has clouds, open its contextual menu and choose Surface Image/Model > Default and use the location scroller to examine the planet’s surface. (c) Which major planet shows the heaviest cratering? (d) Which of these terrestrial planets show evidence of liquid water? (e) What do you notice about Venus’s rotation compared to the other planets?
Use Starry Night™ to examine the Jovian planets Jupiter, Saturn, Uranus, and Neptune. Select each of these planets from Favourites > Explorations. Use the location scroller cursor to examine each planet from different views. (a) Describe each planet’s appearance. Which has the greatest color contrast in its cloud tops? (b) Which planet has the least color contrast in its cloud tops? (c) What can you say about the thickness of Saturn’s rings compared to their diameter?