Apollo special: It's the solar system, stupid

 作者:赫连倘     |      日期:2019-03-14 07:05:01
By Dana Mackenzie WHILE the world watched in fascination as Neil Armstrong and Buzz Aldrin gambolled about on the moon, planetary scientists had their eyes on a different prize. For them, the value of the mission lay in the cargo the mission aimed to bring home, and the astronauts did not disappoint. By the time Armstrong and Aldrin climbed into the lunar module for the last time, they had collected 22 kilograms of moon rocks, enough to fill a small suitcase. Five more Apollo crews brought the total collection of moon rock to 382 kilograms of material, made up of some 2200 individually numbered samples. Three uncrewed Russian landers recovered a further 300 grams of soil. The rocks were billed at the time as a scientific treasure and they didn’t disappoint either. “Our ideas about planetary formation and evolution had to be rewritten from scratch after Apollo,” says geologist Paul Spudis of the Lunar and Planetary Institute in Houston, Texas. Apollo samples decisively laid to rest many myths about the moon. Nobel prizewinner Harold Urey, one of the first great advocates of lunar exploration, had predicted the moon was made of primitive meteoritic material. He was wrong. Some of the rocks looked a lot like Earth rocks, notably the dark basalts that give the lunar maria, or “seas”, their distinctive hue. Others were quite different, such as the ubiquitous jumbled pieces of rock called breccias, which have been smashed up and welded together by millions of years of meteorite impacts. Many of the clues that the lunar rocks contained have taken years to decode,