Planetary Science

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Planetary Science, study of the forces and influences that determine the composition, structure, and evolution of planets and planetary systems. Planetary scientists also study how planetary systems form around other stars. In particular, planetary science is a study of the properties of the Earth compared to the properties of other worlds, which helps explain some of the properties of Earth through the example of other planets.

The origins of modern planetary science can be traced to the Copernican revolution of the 16th and 17th centuries, which led to overturning the old idea that Earth is unique and central in creation. Polish astronomer Nicolaus Copernicus, Italian astronomer and philosopher Galileo, and others showed that the Sun is the central body in Earth’s solar system and that Earth is only one planet among several that orbit the Sun. Continued advances in astronomy have revealed that the Sun is an average star in a universe filled with billions of stars. Recent observations indicate that a significant fraction of the stars in the universe could be encircled by planetary systems—some of which may be similar to Earth’s solar system, and many that are probably quite different.

Modern planetary science draws from many fields of science, including astronomy, physics, chemistry, atmospheric science, and geology. To some degree, the study of planets also requires a biological perspective, for it is now clear that the evolution of the atmosphere and surface environment of at least one planet—Earth—has been radically influenced by the presence of life. Many scientists believe that life may not be limited Earth and may, in fact, be fairly common throughout the universe (see Exobiology). Planetary science is therefore also concerned with life on other planets.

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