Unit 4 Astronomy: the science of the stars天文学(Astronomy)是研究宇宙空间天体、宇宙的结构和发展的学科。内容包括天体的构造、性质和运行规律等。天文学是一门古老的科学，自有人类文明史以来，天文学就有重要的地位。主要通过观测天体发射到地球的辐射，发现并测量它们的位置、探索它们的运动规律、研究它们的物理性质、化学组成、内部结构、能量来源及其演化规律。在天文学悠久的历史中，随着研究方法的改进及发展，先后创立了天体测量学、天体力学和天体物理学。天文学的研究对于我们的生活有很大的实际意义，对于人类的自然观有很大的影响。古代的天文学家通过观测太阳、月球和其他一些天体及天象，确定了时间、方向和历法。这也是天体测量学的开端。如果从人类观测天体，记录天象算起，天文学的历史至少已经有五六千年了。天文学在人类早期的文明史中，占有非常重要的地位。埃及的金字塔、欧洲的巨石阵都是很著名的史前天文遗址。美国著名的女天文学家南西·格蕾丝·罗曼从小痴迷于太空学，被称为“哈勃太空望远镜之母”。A Great Woman ScientistBack in the 1950s few women in the United States worked outside of the 1home, and even fewer earned doctorates( 博 士 学 位 ) or went on to have professional careers. However, as the first chief of astronomy at the US space agency, Nancy Grace Roman is a notable exception(例外). She says, “Certainly by the time I was in seventh grade, I knew I had to have a long education if I wanted to become an astronomer.” Pursuing(追求) her interest in astronomy was not easy. But Roman was determined to become an astronomer and learn everything she could about stars. She went to college, studied science and earned her doctorate in astronomy from the University of Chicago in 1949. She has been working very hard and NASA's current chief astronomer calls her “the mother of the Hubble Space Telescope.” After retiring from NASA in 1979, Roman spends much of her time consulting, teaching and lecturing across the country. Roman hopes she'...
