一光年的距離大得令人難以想象。 The distance of a light year boggles the imagination.
1光年是以每秒186000英里的速度走過(guò)一年的距離，約為6萬(wàn)億英里。 A light year is the distance which light travels at186,000 miles per second in one year, namely6 million million miles.
天津四，天鵝α星在天鵝座最亮的一顆恒星，距地球大約有1，630光年 The brightest star in the constellation Cygnus, approximately1,630 light-years from Earth.
北河二雙子座中的一顆雙星，是這組星中最明亮的一顆，距地球約46光年 A double star in the constellation Gemini, the brightest star in the group, approximately46 light-years from Earth.
