Which design can be made large and produce clearer images?

• A. Radio
• B. Space-based
• C. Refracting
• D. Reflecting

Answer: (D)

Reflecting telescopes can be made very large because mirrors can be supported from behind and manufactured into precise shapes without the weight and bending issues that lenses face. This lets you build big apertures that collect more light and resolve finer details. In addition, mirrors reflect all wavelengths similarly, so there’s no chromatic aberration that blurs the image. Refracting telescopes, by contrast, use lenses that become heavy and distort under their own weight, and different colors bend by different amounts, causing color fringes and blur. Space-based telescopes reduce atmospheric distortion but the practical, scalable way to achieve clear, large images is through a reflecting design.