Astronomy Practice Exam

What is the primary advantage of a reflecting telescope over a refracting telescope?

1. Reflecting telescopes are easier to transport

2. Reflecting telescopes do not suffer from chromatic aberration

3. Reflecting telescopes are cheaper to produce

4. Reflecting telescopes can observe ultraviolet light better

The correct answer is: Reflecting telescopes do not suffer from chromatic aberration

The primary advantage of reflecting telescopes over refracting telescopes lies in their design, which utilizes mirrors to gather and focus light. This construction eliminates the issue of chromatic aberration, a common problem in refracting telescopes caused by the different wavelengths of light being refracted by the lenses at varying degrees. In a refracting telescope, colors can become distorted because glass lenses bend different wavelengths of light differently, leading to images that may have color fringes or a lack of clarity. Reflecting telescopes, on the other hand, use mirrors that reflect light rather than refracting it. Since reflection does not depend on the wavelength of light, all colors are focused to the same point, producing clearer images without the color distortions associated with lenses. This characteristic is particularly advantageous for astronomical observations, where clarity and color accuracy are vital for accurate data gathering and image quality. While factors like transportability, production costs, and light capacity in different spectrums may also favor reflecting telescopes in certain contexts, the absence of chromatic aberration remains a significant reason for their widespread use in both amateur and professional astronomy.