Instead of a concave lens near the eye ... This was the first working reflecting telescope. Other designers proved unable to grind mirrors with a regular curvature, so the reflector remained ...

These "wings" must now be rotated through 90 degrees to achieve the desired 6.5m-wide concave shape ... primary and secondary mirrors Webb succeeds the Hubble Space Telescope, which, when it ...

Gregory's reflecting telescope (standing) dates from the 18th century. Reflecting telescopes use a concave mirror as an objective. Since ancient times, time has been measured by the position of the ...

The golden reflector, the centrepiece of the new James Webb telescope, was straightened out on Saturday into its full, 6.5m-wide, concave shape. The mirror had been folded like a drop-leaf table ...

He replaced the concave lens with a second convex ... Light travels into the telescope, bounces off a curved mirror at the ...