Planetary science, also known as planetology and closely related to planetary astronomy, is the science of planets, or planetary systems, and the solar system. Incorporating an interdisciplinary approach, planetary science draws from diverse sciences and may be considered a part of the Earth sciences, or more logically, as its parent field. Research tends to be done by a combination of astronomy, space exploration (particularly robotic spacecraft missions), and comparative, experimental and meteorite work based on Earth. There is also an important theoretical component and considerable use of computer simulation. Astrogeology is a major component of planetary sciences.