Word: geologist
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...particles were 4.6 billion years old -the apparent age of the moon itself -most of the rocks were about 1 billion years younger. How could there be such a huge age gap between material picked up only a few feet apart? "This is a major puzzle," says Rice University Geologist Dieter Heymann. One small rock fragment, though, was considerably older than the others: 4.44 billion years. Caltech Geologist G. J. Wasserburg, who calculated its age, believes that still older rocks dating back to the very creation of the moon will probably be found in the unexplored lunar highlands...
...late Princeton geologist Harry Hess provided an imaginative answer to the puzzle. Refining a rough idea suggested a generation earlier, Hess proposed that the earth's mantle is really a giant convection system. Like hot air in a room, he suggested, material heated by radioactive elements in the earth's interior slowly rises out of a relatively fluid layer of the earth's mantle called the asthenosphere. This lava surfaces at the mid-ocean ridges; hence, the higher water temperatures. As it flows away from the ridges, it hardens into a more rigid layer called the lithosphere...
...huge, flat, featureless areas like the 1,200-mile-long plain called Hellas. There are also vast expanses of jumbled, chaotic terrain, whose short ridges and small valleys are unlike any features on the moon and do not exist on so large a scale on earth. Concludes Caltech Geologist Robert Sharp: "Mars is definitely...
...apparently rough, uneven splotches that lose their geometric-looking form on closer examination. Far from being the outpost of an advanced civilization, Mars more and more seems to be something of a primordial version of the earth, as it might have been billions of years ago. Says Caltech Geologist Robert Sharp: "We are looking at what could be baby pictures of the earth...
Despite such minor hitches, scientists were in unanimous agreement on the value of the expedition. The landing site, especially, pleased geologists. "It is a very much rockier surface than we might have expected," said NASA Geology Consultant Eugene Shoemaker, who thinks that it afforded a far wider sampling of the lunar surface than would have been found at a smoother landing site. Boulders ejected from craters as far away as 600 miles might well be in the area, he added. Another unexpected dividend, said NASA Geologist Ted Foss, was that many of the rocks may have come from the large...