Here's why:
* Astronomy is the scientific study of celestial objects (like stars, planets, moons, comets, etc.) and phenomena that originate outside the Earth's atmosphere.
* Physics is a broader science that deals with the fundamental constituents of the universe and the laws that govern their behavior. While physics plays a crucial role in understanding astronomical phenomena, astronomy focuses specifically on the celestial realm.
So, while physics provides the theoretical framework for understanding stars and planets, astronomy is the science that studies them directly.
