Astronomy is the study of objects and phenomena beyond Earth, whereas
cosmology is a branch of
astronomy that studies the origin of the universe and how it has evolved. For example, the big bang, the origin of the chemical elements, and the cosmic microwave background are all subjects of
cosmology.Astronomy is the study of the universe and what resides outside of the Earth’s atmosphere (such as stars, galaxies, nebulae, etc. Astronomers examine the positions, motions, and properties of these celestial objects.
Cosmology is actually a subset and branch of astronomy, but it looks specifically at the origin and evolution of the universe.Astronomy is a science that focuses on the solar system and galaxy, while cosmology, on the other hand, explores the origin and evolution of the universe. It attempts to solve the mystery of how the universe and time began. Hence, the basic difference between astronomy and cosmology is the
scope of the universe that is studied.
Cosmology, on the other hand, focuses on the nature of the universe itself, as Ask A Physicist reports. It goes all the way back to the Big Bang and its current state, and it also focuses on the ultimate fate of the universe. While cosmology concentrates on the universe as a whole, astronomy concentrates on individual celestial objects.