Astronomy Practice Exam

What type of telescope did Isaac Newton design?

1. Refracting telescope

2. Reflecting telescope

3. Radio telescope

4. Cassini telescope

The correct answer is: Reflecting telescope

Isaac Newton designed the reflecting telescope, which uses a curved mirror to collect and focus light. This design represented a significant advancement over the existing refracting telescopes of his time, which used lenses to bend light. The problem with refracting telescopes was that lenses could introduce color distortions, known as chromatic aberration, which affected image clarity. Newton's reflecting telescope eliminated these issues by using a mirror, allowing for clearer images without the distortions associated with lenses. This innovation paved the way for future telescope designs and significantly contributed to the field of astronomy by enhancing observational capabilities. The design ethos of substituting mirrors for lenses allowed for larger apertures and improved performance, making the reflecting telescope a foundational invention in astronomical studies.