By studying the filtered starlight, astronomers can determine such a planet's atmospheric composition and also the direction and velocity that any gas lost to space is moving.
通过研究过滤后的恒星光,天文学家确定该行星大气的组成,以及气体被吹入太空的方向以及速率。
3
If I had here a hammer this is a hammer and there were no external forces I would be somewhere in outer space and it would have a certain velocity.