Astronomy, Astrophysics, and Space Science

[Cornell University]

Astronomy, astrophysics, and space science are closely related fields that study celestial objects and the universe. Space science is the broadest category, encompassing all scientific study of outer space. Astronomy is the observational and descriptive side, focusing on what and where things are in the cosmos. Astrophysics uses physics and chemistry to understand how and why these phenomena occur. 

1. Space science: The umbrella term for the scientific study of outer space and the universe beyond Earth's atmosphere. 

• Scope: Encompasses a wide range of disciplines that work together to understand the universe, including its origins and future.

2. Astronomy: The scientific study of celestial objects, space, and the universe through observation and description. 

• Focus: Answers "what and where" questions, cataloging and describing objects like stars, planets, and galaxies.
• Method: Primarily involves observation and data gathering using instruments like telescopes.

3. Astrophysics: A branch of space science that uses the principles of physics and chemistry to explain astronomical phenomena.

• Focus: Answers "how and why" questions, exploring the underlying physical and chemical mechanisms behind celestial events.
• Method: Employs theoretical and mathematical models to understand the data gathered by astronomers.
• Topics: Examples include the birth, life, and death of stars, the formation of galaxies, and the nature of the cosmic microwave background.