parsecn.
英 'pɑːsek | 美 'pɑr,sɛk
中文n. 秒差距（表示天体间距离的单位）
词根词源
parsec (n.)interstellar distance measure, 1913, from first elements of parallax second. It is the distance at which an object has parallax (viewed from Earth) of one second of arc, or about 3.26 light-years.
关键词