Stars - A Guide to the Constellations, Sun, Moon, Planets, & Other Features of the Heavens
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Galaxy, the net movement of the solar system is toward Cygnus. LYRA, THE LYRE is a small constellation marked by the splendor of Vega, its brightest star. Blue-white Vega, magnitude 0.1, 26 light-years away, is the brightest summer star. Between the pair of 3rd-magnitude stars at the end of the diamond-shaped constellation is the famed Ring Nebula, 5,400 light-years away here. A large telescope is needed to see its details. One of the 3rd-magnitude stars in Lyra is a double star. The two stars.
Debris into our atmosphere. In space such particles are termed meteoroids. As they hit the atmosphere a hundred miles up at a speed of 25 miles per second, they burn up. About 5-10 sporadic meteors can be seen each hour on a dark night in a good location. Several times a year the earth passes through meteoroid swarms (usually along the orbits of comets) and we may see many more meteors per hour: a meteor shower. About 100 million meteoroids, a total of about 10 tons, hit earth each day. Most.
Thousands of craters, some caused by meteors, some perhaps by ancient volcanoes, cover the rest of the moon’s surface. These range from � mile to 150 miles across, with steep, rocky walls jutting upward as high as a mile or two. Sometimes an isolated peak is within the crater. Bright streaks or rays extend in all directions from some craters. Besides the craters and plains (called seas by early astronomers who thought they were full of water), the moon has mountain ranges with peaks three, four,.
Size. The asteroid Ceres is compared (3) to Texas for size, and the moon is compared (4) to the United States. A comet’s orbit (5) appears in red. Our solar system may be only one of billions in the universe. So far, life is known to exist only on earth. THE SUN is the nearest star. Compared to other stars it is of just average size; yet if it were hollow, over a million earths would easily fit inside. The sun’s diameter is 860,000 miles. It rotates on its axis about once a month. The sun is.
Of the density of air. The more usual stars have a density fairly close to that of the sun. White dwarfs are so dense that a pint of their material would weigh 15 tons or more on earth. The companion to Sirius is 25,000 times more dense than the sun. Neutron stars are billions of times denser. MOTIONS OF STARS Our sun is moving about 12 miles per second toward the constellation Hercules. Other stars are moving too, at speeds up to 30 miles per second or faster. Arcturus travels at 84 miles per.