The U.S. has plans to build a 30-meter telescope, while the Europeans are thinking about 39-meter telescope. What technological innovation allows astronomers to be thinking about telescopes with that large an aperture?
A) they can put telescopes on tall mountains now, which we could not ever do before
B) they can build much larger lenses for their telescopes with new kinds of plastics
C) adaptive optics technology allows them to design a huge mirror which hardly weighs anything
D) the mirror in these telescopes will be constructed from many smaller mirrors which will work together
E) those big telescopes are just a dream right now; no one can think of a technology for building them.

Question

Quizplus · Accepted Answer

The technological innovation that allows for telescopes with such large apertures is the use of segmented mirrors. Large mirrors, even those made of lightweight materials, are inherently difficult to manufacture and maintain flatness. However, using segmented mirrors allows for the construction of larger mirrors by combining many smaller segments, each of which can be more easily manufactured and adjusted.

The US Has Plans to Build a 30-Meter Telescope, While the the Europeans