What is the difference between the study of astronomy and the study of cosmology?

1 Answer
Jan 1, 2016

Cosmology is the study of the whole universe. Astronomy is the study of objects within the universe, such as stars and planets.


Astronomy and cosmology are similar in many respects, but they deal with things on vastly different scales.

Let's start with astronomy. This is the study of objects like stars, planets, comets and asteroids. Some astronomers devote their careers to studying one body, like Pluto, or a particular galaxy in the sky. They can tell us about things like the evolution of the solar system or the precise orbits of the planets.

Cosmology is the study of the universe as a whole. Cosmologists are people who work hard to understand the biggest thing we know of - the entire universe! Thanks to their data and experiments, we can say confidently that the universe is expanding at an increasing rate. This has profound implications, because it suggests that something is pulling the universe apart, against the force of gravity.