Mindblown: a blog about philosophy.
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Impact Craters
Learning Objectives By the end of this section, you will be able to: The Moon provides an important benchmark for understanding the history of our planetary system. Most solid worlds show the effects of impacts, often extending back to the era when a great deal of debris from our system’s formation process was still present. On Earth,…
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The Lunar Surface
Learning Objectives By the end of this section, you will be able to: General Appearance If you look at the Moon through a telescope, you can see that it is covered by impact craters of all sizes. The most conspicuous of the Moon’s surface features—those that can be seen with the unaided eye and that make up the feature…
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General Properties of the Moon
Learning Objectives By the end of this section, you will be able to: The Moon has only one-eightieth the mass of Earth and about one-sixth Earth’s surface gravity—too low to retain an atmosphere (Figure 9.2). Moving molecules of a gas can escape from a planet just the way a rocket does, and the lower the gravity, the…
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Thinking Ahead
The Moon is the only other world human beings have ever visited. What is it like to stand on the surface of our natural satellite? And what can we learn from going there and bringing home pieces of a different world? We begin our discussion of the planets as cratered worlds with two relatively simple…
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Collaborative Group Activities
Collaborative Group Activities
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For Further Exploration
For Further Exploration Articles Earth Collins, W., et al. “The Physical Science behind Climate Change.” Scientific American (August 2007): 64. Why scientists are now confident that human activities are changing our planet’s climate. Glatzmaier, G., & Olson, P. “Probing the Geodynamo.” Scientific American (April 2005): 50. Experiments and modeling that tell us about the source and reversals of Earth’s…
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Cosmic Influences on the Evolution of Earth
Learning Objectives By the end of this section, you will be able to: In discussing Earth’s geology earlier in this chapter, we dealt only with the effects of internal forces, expressed through the processes of plate tectonics and volcanism. On the Moon, in contrast, we see primarily craters, produced by the impacts of interplanetary debris such…
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Life, Chemical Evolution, and Climate Change
Learning Objectives By the end of this section, you will be able to: As far as we know, Earth seems to be the only planet in the solar system with life. The origin and development of life are an important part of our planet’s story. Life arose early in Earth’s history, and living organisms have been interacting…
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Earth’s Atmosphere
Learning Objectives By the end of this section, you will be able to: We live at the bottom of the ocean of air that envelops our planet. The atmosphere, weighing down upon Earth’s surface under the force of gravity, exerts a pressure at sea level that scientists define as 1 bar (a term that comes from…
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Earth’s Crust
Learning Objectives By the end of this section, you will be able to: Let us now examine our planet’s outer layers in more detail. Earth’s crust is a dynamic place. Volcanic eruptions, erosion, and large-scale movements of the continents rework the surface of our planet constantly. Geologically, ours is the most active planet. Many of the…
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