The first spectacles, designed to correct farsightedness, bore glass magnifiers ... however, most optical telescopes in use in the 21st century derive from the two types developed in the 17th ...

On this list, we've brought you a selection of eyepieces, each of them suited to different types of astronomy. If you need further guidance, head to our best eyepieces for telescopes FAQs at the ...

New optical technologies ... was the introduction of silvered-glass mirrors by Foucault 2 in 1857 (Fig. 1d). This opened the way for the great reflecting telescopes of the twentieth century ...

Telescopes can be categorized in three optical design types. Reflecting: A reflecting telescope, also called a reflector telescope, is an optical telescope that uses a single or combination of ...

NASA's James Webb Space Telescope is the largest and most powerful telescope ever launched to space. Its mirror is composed of 18 individual segments that have been aligned so accurately, that they ...

More than 100 years ago, astronomer George Ellery Hale brought our two Pasadena institutions together to build what was then the largest optical telescope in the world. The Mt. Wilson Observatory ...