Cosmology is a fascinating topic in Astronomy and Physics. It is the study of the origin and evolution of the universe. While other areas of astronomy seek to understand various objects, systems and phenomena in space (such as stars, planets, supernovae and more), cosmologists want to understand very fundamental questions. What space is made of? How long has the universe existed and how long will it continue to exist? How was the early universe different from the universe today, and how will the universe change as it ages?
Cosmology is sometimes considered a subfield of astronomy, but this is not completely accurate. Astronomy is the study of the contents of the universe. Modern cosmology draws from many fields including astronomy, physics and others, to study the laws of nature and everything that is subject to these laws.
Image credit: Alice Hopkinson, LCO