planetary science
Academic field studying planets, moons, and planetary systems, including geology, atmospheres, and formation.
He is majoring in planetary science at university.
Advances in planetary science have revealed details about the Martian environment.
Astronomy focuses on celestial objects and the universe as a whole, while 惑星科学 specifically studies planets and planetary systems.
Earth science studies the Earth; 惑星科学 applies similar methods to other planets and moons.
Compound of 惑星 (planet) and 科学 (science). A straightforward modern academic term.