SSS 2011-03-31

This is Scientific Americans 60-Second Science. Im Karen Hopkin. This will just take a minute. Its been nearly 20 years since astronomers first identified a planet outside our solar system. More than 500 exoplanets have been discovered since then, ye

发表于:2018-12-24 / 阅读(76) / 评论(0) 分类 Scientific American(三)月
最新学习文章
热门学习文章