What is the primary purpose of an astronomical telescope?

The astronomical telescope is a central apparatus used to study distant planets, stars and moons from the Earth. Astronomer Galileo Galilei famously used the earliest telescopes in 1610 to prove the heliocentric solar system theory put forth by Nicolaus Copernicus in the early 16th century.

Using light reflection, an astronomical telescope enhances the brightness of a planet from a vantage point on the Earth. This factor allows for much greater detail than one can see with the naked eye. Enhanced resolution improves clarity. The magnifying power of top telescopes also make distant planets and solar bodies appear much larger to the observer.