Science: Treasure from the Moon

Even to veteran splashdown watchers Apollo 16's return to earth last week was a spectacle of rare beauty. The slow blossoming of the spacecraft's three orange and white parachutes against the bright, azure sky seemed designed for maximum drama. Then, in a final demonstration of precision, the spacecraft Casper hit the water only one mile off the bow of the recovery carrier Ti-tonderoga. Once out of its natural element, Casper immediately capsized; it bobbed nose down in the choppy South Pacific for five minutes until the astronauts—strapped in upside-down and rapidly becoming queasy—righted it with three flotation bags. That brief misadventure could not come close to dampening the exuberance of Astronauts John Young, Charles Duke and Ken Mattingly as they arrived for their red-carpet welcome on the Ticonderoga's flight deck. "By golly," said Young, "you taxpayers—we taxpayers—got your money's worth."

No doubt about it. For all the problems they had encountered on the way to the moon and in the process of setting up their experiments, the Apollo 16 astronauts scored a scientific triumph. Young and Duke spent 20 hours and 14 minutes prowling the lunar surface, only three-quarters of an hour short of their original goal. They also collected so much moon material that they nearly ran out of collection bags. Most significant of all, the next to last Apollo mission has already given scientists valuable new details about the terrain that makes up more than 80% of the lunar surface: the rugged and ancient highlands.

Wrong Reasons. Some of the findings were surprising indeed. Although geologists had forecast that there would be a trove of heat-formed crystalline rocks on the Descartes region's Cayley Plains, most of what the astronauts and their cameras saw were fragments called breccias, which are forged together from still more ancient rocks. At the very least, that unexpected finding means that the Cayley Plains were formed, not simply by volcanic flows, but by far more complex geological processes. Said NASA Geochemist Robin Brett: "We went to the right place for the wrong reasons."

To complicate the picture further, Young and Duke logged the highest magnetic readings ever recorded on the moon's surface, possibly the residue of an ancient magnetic field. The readings thus provide new support for the disputed theory that the moon once rotated rapidly and had a molten iron core. Acting like a dynamo as the moon spun through space, this core could have created a strong lunar magnetic field.

Much of the lunar material was gathered at the beginning of the week during the third and final EVA (extravehicular activity) by Young and Duke on the plains of Descartes. With helpful navigational guidance from Houston, 240,000 miles away, the astronauts drove their $12 million moon cart to the very rim of a large feature called North Ray Crater, some three miles away from the lunar lander, Orion. As the rover's television camera followed them, they threaded their way down North Ray's steep slopes, going deeper into a large crater than any of the eight previous moon walkers. Inside the crater wall, they chipped away at a huge house-sized boulder that might be at least 4 billion years old.