What is the difference between Astronomy and Astrophysics?
This is actually a question that can be answered very simply indeed if you take a step back and look logically. The two words/fields though, are inextricably linked in the world of today’s study of the universe and all that exists outside of our planets atmosphere, and each deserves credit by way of some definition and explanation.
Astronomy, in its most basic definition, is the study of celestial objects outside the Earth’s atmosphere. To take it to another level, within that general study we can say that astronomy deals with the study of the evolution, motion, chemistry and physics of celestial objects, and also the origin, formation and development of the universe as a whole.
Astrophysics on the other hand, is the branch of Astronomy that specifically focuses on the physical properties of the universe and the celestial objects within it, including their behaviour and interactions.
I am sure that people who study in this field do not differentiate between the two as basically as this, because professional astronomers and astrophysicists today work so closely together in all fields, using each others knowledge to further mankind’s, that there really is scarcely a need to separate the two professionally. In fact, modern professional astronomy is often considered synonymous with astrophysics, and it is only the history of particular organisations that have differentiated between the two in such things as departmental naming.
However, on a very fundamental and everyday level, away from the world of professional astronomers and astrophysicists, it could be argued that it is very easy to define the difference between the two words.
Consider for a moment taking a step outside your back door tonight. Adam in Atlanta to Zoe in Zumbro Falls. All of us take a look up at the night sky and begin to contemplate the origins of what we see, or how far away the stars are, or what that one particular hazy object is that we can’t quite focus on.
In a matter of seconds, it could be argued that we have all become amateur astronomers, studying and pondering on the universe as a whole. However, I don’t think, in that same scenario, that it could be argued that we would have become overnight amateur astrophysicists, specifically focusing on the physical properties of the objects we’re looking at or how they all interact.
And there for me is the fundamental difference between the words astronomy and astrophysics. Astronomy is a broad umbrella of studying all things celestial, where astrophysics is a specific and detailed examination of the physics behind the interactions of parts of that umbrella.