Describe the kinds of features that can be seen on the Moon with a small telescope.
Are impact craters on the Moon the same shape as the meteoroids that made the impact? Explain your answer.
Why is Earth geologically active while the Moon is not?
Rocks found on the Moon are between 3.1 and 4.47 billion years old. By contrast, the majority of Earth’s surface is made of oceanic crust that is less than 200 million years old, and the very oldest Earth rocks are about 4 billion years old. If Earth and the Moon are essentially the same age, why is there such a disparity in the ages of rocks on the two worlds?
What kind of surface features are found on Mercury? How do they compare to surface features on the Moon? Why are they probably much older than most surface features on Earth?
If Mercury is the closest planet to the Sun and has such a high average surface temperature, how is it possible that ice might exist on its surface?
What is flake tectonics? Why does Venus exhibit flake tectonics rather than plate tectonics?
How was water most recently discovered on Mars?
How was water most recently discovered on Earth’s Moon?
Why do ice rafts indicate the existence of a subsurface ocean on Europa?
NASA is planning a new series of manned missions to the Moon. Compare the advantages and disadvantages of exploring the Moon with astronauts as opposed to using mobile, unmanned instrument packages.
Describe how you would empirically test the idea that human behavior is related to the phases of the Moon. What problems are inherent in such testing?
Imagine that you are planning a lunar landing mission. What type of landing site would you select? Where might you land to search for evidence of recent volcanic activity?
If you were planning a new mission to Mercury, what features and observations would be of particular interest to you?
The total cost of the Mars Global Surveyor mission was about $154 million. (To put this number in perspective, in 2000 the U.S. Mint spent about $40 million to advertise its new $1 coin, which failed to be accepted by the public. Several recent Hollywood movies have had larger budgets than the Mars Global Surveyor.) Does this expenditure seem reasonable to you? Why or why not?
Is it worthwhile for scientists to actively search for water on planets and satellites?
The image of the Moon in Figure 6-2 reveals numerous craters. Using the idea that the Moon’s landscape can only be changed by impacts, make a rough sketch showing 10 of the largest craters and label them from oldest (those that showed up first) to youngest (the most recent ones). Explain your reasoning and any uncertainties.
Consider the image of Mars in Figure 6-1. Draw a circle on your paper roughly 5 cm in diameter and, taking turns, have each person in your group sketch a different region of Mars. How is your collaborative sketch different from the other images of Mars found throughout the book?
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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 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 Mercury. Select Favourites > Explorations > Mercury from the menu. Stop the advance of time and use the Zoom controls and the location scroller to examine the surface of the planet Mercury. Estimate the diameters of the largest craters on Mercury’s surface by measuring their size on the screen with a ruler and comparing these diameters to the diameter of Mercury. (a) What are the diameters (in km) of the largest craters on Mercury? (b) Zoom in to examine the surface features of Mercury in more detail and compare these features with those of our Moon. Comment on the similarities and differences between these two planetary objects, neither of which has an atmosphere (i.e., presence of craters, light-ray patterns, maria, peaks within craters).
Use Starry Night™ to examine Mars. Open Favourites > Explorations > Mars Surface. Use the Zoom controls and the location scroller to explore this planet’s surface features. You will notice that four volcanoes (Mons) and the Valles Marineris have been labeled. (a) Which of the volcanoes appears to be the largest? (b) Right-click on Mars (Ctrl-click on a Mac) and select Markers and Outlines… from the contextual menu. In the Mars Markers and Outlines dialog window, click the lower radio button to the left of the List label. Then in the dropdown box to the right of the List label, choose Type. In the rightmost dropdown box, select Crater as the type of feature and then click the Check all Shown button. Describe the distribution of craters on the Martian surface. (c) What does the distribution of craters in the region around the volcanoes suggest about the time at which these volcanoes formed on Mars?