2 sentences for 轨迹 (guǐ​jì — trajectory)

1. 这颗彗星的运行轨迹非常特殊。

   zhè kē huì​xīng de yùn​xíng guǐ​jì fēi​cháng tè​shū.

   The trajectory of this comet is very unusual.

   Source: Dong Chinese Dictionary

2. 天文学家正在观测木卫一的运动轨迹。

   tiān​wén​xué​jiā zhèng​zài guān​cè Mù​wèi Yī de yùn​dòng guǐ​jì.

   Astronomers are observing the trajectory of Io.

   Source: Dong Chinese Dictionary