Science 7月21日 发文:  "A century of astronomy revealed Earth’s place in the universe" (https://www.sciencenews.org/article/space-exoplanet-century-astronomy-earth-universe).

   一个世纪前，银河系是整个已知宇宙。 我们不知道是什么让星星发光，已知只有一颗恒星——我们自己的太阳——庇护着所有行星。在这些行星中，人类只探索过一个：地球。

一百年后的今天,…

Early astronomers placed Earth at the center of the universe, as in this Ptolemaic map from 1568, which shows the distances (left) and times of revolution around Earth (right) of the sun and other planets.