As construction continues on ESO's Extremely Large Telescope, the observatory shared some stunning photos of the site as the ...

Webb can see very distant galaxies thanks to its huge primary mirror, which is the largest that has ever been launched into space. Telescopes are often put into space because they can sit above ...

The Hale Telescope on Palomar Mountain in California, the world’s largest mirror for much of the last century, begat Keck, twins that took over as largest with 10-meter mirrors in the 1990s.