interplanetary diffusion

例句：

1. 1. The spacecraft is designed to travel between planets.
   这个太空船的设计是用于在行星之间旅行。
2. 2. The discovery of exoplanets has expanded our understanding of the universe.
   发现系外行星已经扩展了我们对宇宙的理解。
3. 3. Interplanetary missions are crucial for studying the formation of stars and galaxies.
   星际任务对于研究恒星和星系的形成至关重要。