Venus - Astronomy Matters

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Venus . . .

Venus, was a major goddess in Roman mythology. She originally was a protector of gardens. Later, she took on the myths and qualities of Aphrodite, the goddess of fertility, love, and beauty in Greek mythology. Venus symbolized the creative force that sustains all life.

Venus plays a part in a famous myth called the Judgment of Paris. Venus and the goddesses Juno and Minerva all claimed a golden apple, a prize reserved for the most beautiful goddess. The god Jupiter ordered Paris, the son of King Priam of Troy, to choose the most beautiful of the three. Paris awarded the apple to Venus. In revenge, Juno and Minerva made certain that Troy was destroyed during the Trojan War.

Venus is known as the Earth's "twin" because the two planets are so similar in size. The diameter of Venus is about 7,520 miles (12,100 kilometers), approximately 400 miles (644 kilometers) smaller than that of the Earth. No other planet comes nearer to the Earth than Venus. At its closest approach, it is about 23.7 million miles (38.2 million kilometers) away. Its mean (average) distance from the sun is about 67.2 million miles (108.2 million kilometers), compared with about 93 million miles (150 million kilometers) for the Earth and about 36 million miles (57.9 million kilometers) for Mercury.

Venus is brighter than any other planet or even any star. At certain times of the year, Venus is the first planet or star that can be seen in the western sky in the evening. At other times, it is the last planet or star that can be seen in the eastern sky in the morning. When Venus is near its brightest point, it can be seen in daylight.

When viewed through a telescope, Venus can be seen going through "changes" in shape and size. These apparent changes are called phases, and they resemble those of the moon. They result from different parts of Venus's sunlit areas being visible from the Earth at different times. Venus can be seen near the opposite side of the sun about every 584 days. At this point, almost all its sunlit area is visible. As Venus moves around the sun toward the Earth, its sunlit area appears to decrease and its size seems to increase. After about 221 days, only half the planet is visible. After another 71 days, Venus nears the same side of the sun as the Earth, and only a thin sunlit area can be seen. When Venus is moving toward the Earth, the planet can be seen in the early evening. When moving away from the Earth, Venus is visible in the early morning.
Mountains of Venus

Venus has a variety of surface features, including level ground, mountains, canyons, and valleys. About 65 percent of the surface is covered by flat, smooth plains. On these plains are thousands of volcanoes, ranging from about 0.5 to 150 miles (0.8 to 240 kilometers) in diameter. Six mountainous regions make up about 35 percent of the surface of Venus. One mountain range, called Maxwell, is about 7 miles (11.3 kilometers) high and about 540 miles (870 kilometers) long. It is the highest feature on the planet. In an area called Beta Regio is a canyon that is 0.6 mile (1.0 kilometer) deep.

Venus's clouds-and the great quantity of carbon dioxide in the atmosphere-seem to trap much of the solar energy at the planet's surface. The temperature of the uppermost layer of Venus's clouds averages about 55 °F (13 °C). However, the temperature of the planet's surface is about 870 °F (465 °C), higher than that of any other planet and hotter than most ovens.