Difference Between Astronomy and Cosmology
By Marc Gordon - July 30, 2021

Both astronomy and cosmology are studies of celestial objects but in very different senses. The scopes and areas of the two sciences are primarily the difference between them, the purpose of this article is to explain those differences in more detail.

Table Summary

Study of the positions, motions, and relationships of stars and planetsStudy of the development, birth, and organization of the universe as a whole
Mostly observational, with little theoretical studyThe majority of the study is theoretical, seldomly relying on observational data
A diverse range of subcategories comprises science: astrophysics, observational astronomy, and astrobiology, to name a few.Broken up into theories: Big Bang theory, Steady State theory, String theory, and Inflationary theory, to name a few
Most studies object relatively close to earth like those in our solar systemStudies galaxies as clusters and the universe as a whole
Helps us gain more information about stars and planets and their potential for human settlementHelps us understand the size of the universe and how it will end


Astronomy’s invention coincides with human awareness. Since human beings have been able to, we have been looking to the stars and trying to understand them and use them to our benefit. Astronomy is an umbrella term that comprises many different fields of study that all relate to celestial bodies Рsome examples include; astrophysics, astrobiology, and observational astronomy. Astronomy is for the most part an observational school with a focus on observational data and very few theoretical tools. The aim of the school is to assist us in gaining more information about the objects within our solar system and helping us navigate which planets may be hospitable to human life.

Cosmology really hit its stride in the late 1900s and the early 2000s with the discovery of the Big Bang and other major leaps in physics and mathematics. Cosmology is a specific study of the universe as a whole with a concentration on its formation, structure, and conclusion. As such it is predominantly a theoretical study. The aim of science is to allow us to better understand the size of the universe and how it will end one day.

Astronomy VS Cosmology

The main difference between astronomy and cosmology is in the scale and scope of the study. Astronomy is celestially local with a focus on those bodies that exist within our solar system and cosmology is far larger in scale with a focus on the universe in its entirety. As such astronomy is observational in nature and cosmology is far more theoretical.