Jeff Smith, age 12, of Williamsport, Pa., for his question:
HOW BIG ARE SATURN'S RINGS?
The planet Saturn is enormous and bright enough to be seen from a distance of almost a billion miles. However, human vision is not keen enough to detect its razzle dazzle rings from the earth. They were discovered way back in 1609, when Galileo trained his small telescope on the heavens. Since then astronomers have measured them, but research on their mysterious materials still goes on.
If Saturn could replace the planet earth, the outer edge of its golden rings would reach more than one third of the distance to the moon. The huge planet is 763 times larger than the earth and nearly 10 times farther from the sun. Its bulky materials are lighter than water, though because of its immense size it is almost 100 times more massive than our dense little earth.
A day on Saturn lasts only about 10 1/2 earth hours, and its speedy rotation causes a great bulge around its equator. The dazzling rings are directly above the equator, and the lower level is estimated to begin just a few thousand miles above the surface. The diameter of the outer ring is 171,000 miles, which is about 2.3 times wider than the equatorial diameter.
The stupendous rings are flat and estimated to be no thicker than about 10 miles. Until quite recently, it was assumed that they were made from mini particles, perhaps including tiny ice fragments that reflect sparkling specks of sunlight. Then, early in the 1970s, earth based radar devices detected sizable solid chunks, somewhat like large pebbles and perhaps boulders.
The flat ring system is separated by three major spaces and several smaller ones. The middle ring is by far the brightest and estimated to be about 16,000 miles wide. The inner and outer rings are narrower and somewhat duller.
As the Space Age yields masses of new information, some of our old ideas about the planets have had to be revised. For example, Saturn and Jupiter were thought to be cold outer planets. We now know that both give off more radiation than they get from the sun. The big planets are warmer than we thought.