A-ring. These rings lie respectively from
92,200 to 117,500 and from 121,000 to 136,200 kilometers (57,300 to 73,000 and 75,200 to
84,600 miles) from the center of Saturn yet are
only a few hundred meters (yards) thick. The
equatorial radius of Saturn is 60,000 kilometers (37,300 miles). For comparison, the Earth's
equatorial radius is 6,400 kilometers (4,000
miles).

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Figure 1.13. Saturn and its rings depicted by NASA's
Voyager 2 spacecraft on July 21, 1981, when the spacecraft was 34 million kilometers (21 million miles) from the planet.

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Figure 1.14. Illustration of successive phases of the “dark star” Venus seen from Earth as both orbit the Sun (see
figure 1.5). (Top left) Venus is just past its farthest point from the Earth (Superior Conjunction), so
its image is relatively small and gibbous. (Top
middle) The image becomes larger and less
gibbous as it approaches the Earth and reaches
maximum elongation. (Top right) The image becomes crescent. (Bottom row) Venus appears
larger and its phase more crescent as it nears its
closest point to the Earth (Inferior Conjunction).

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Figure 2.1. The Moon as seen through Gainer's reconstruction of the Digges telescope (exposure 1/20sec, ISO 100, 5-megapixel camera, good seeing).

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